Ask OpenScientist

Ask a research question about Obsessive-Compulsive Disorder. OpenScientist will conduct autonomous deep research using the Disorder Mechanisms Knowledge Base and PubMed literature (typically 10-30 minutes).

Submitting...

Do not include personal health information in your question. Questions and results are cached in your browser's local storage.

3
Mappings
1
Inheritance
5
Pathophys.
5
Phenotypes
2
Hypotheses
2
Gaps
11
Pathograph
7
Genes
6
Medical Actions
5
Differentials
3
Trials
10
References
1
Deep Research
🏷

Classifications

Harrison's Chapter
NEUROLOGIC
🔗

Mappings

MONDO
MONDO:0008114 obsessive-compulsive disorder
skos:exactMatch MONDO
Primary MONDO disease identifier for obsessive-compulsive disorder.
NCIT
NCIT:C88411 Obsessive Compulsive Disorder
skos:exactMatch MONDO
MONDO cross-references NCIT C88411 for obsessive-compulsive disorder.
ICD-10-CM
NCIT
NCIT:C88411 Obsessive Compulsive Disorder
skos:exactMatch MONDO
MONDO cross-references NCIT C88411 for obsessive-compulsive disorder.
👪

Inheritance

1
Multifactorial (polygenic) HP:0010982
OCD is a heritable, highly polygenic disorder; twin heritability is roughly 27-47% in adults and 45-65% in children, and common variants distributed across thousands of loci account for most of the SNP-based heritability.
Polygenic inheritance
Show evidence (1 reference)
PMID:40360802 SUPPORT Human Clinical
"We estimated that ~11,500 genetic variants explained 90% of OCD genetic heritability."
Heritability distributed across ~11,500 variants establishes highly polygenic inheritance.

Mechanistic Hypotheses

2
Canonical CSTC Circuit / Serotonergic-Glutamatergic Model
canonical_cstc_serotonergic_glutamatergic CANONICAL
OCD arises from hyperactivity and imbalance within cortico-striato-thalamo- cortical (CSTC) loops (orbitofrontal cortex, anterior cingulate cortex, caudate, thalamus), shaped by serotonergic, glutamatergic, and dopaminergic neurotransmission. The selective efficacy of serotonin reuptake inhibitors, consistent functional-imaging evidence of CSTC hyperactivity, and benefit of CSTC-targeted neuromodulation (TMS, deep brain stimulation) converge on this model.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"Functional imaging studies in OCD show consistent evidence for increased activity in brain regions that form a cortico-striato-thalamo-cortical (CSTC) loop."
Imaging evidence for CSTC hyperactivity anchors the canonical model.
Emerging Neuroimmune / MHC Contribution
emerging_neuroimmune_mhc EMERGING
Genome-wide association implicates the major histocompatibility complex (MHC) region in OCD risk, and PANDAS links streptococcal infection to acute-onset OCD, suggesting a neuroimmune/neuroinflammatory contribution that remains to be mechanistically resolved.
Show evidence (1 reference)
PMID:40360802 PARTIAL Human Clinical
"multiple genes in the major histocompatibility complex (MHC) region"
GWAS implication of the MHC region motivates a neuroimmune hypothesis, though the causal mechanism is unresolved.
?

Discussions and Knowledge Gaps

2
Why are serotonin reuptake inhibitors preferentially effective in OCD when no consistent primary serotonergic abnormality has been identified, and what is the true molecular target of their anti-obsessional effect?
KNOWLEDGE GAP OPEN gap_ocd_serotonergic_paradox
Attached to
pathophysiology#Serotonergic Neurotransmission Dysregulation treatment#Selective Serotonin Reuptake Inhibitors
The serotonergic hypothesis of OCD rests almost entirely on the selective therapeutic response to SRIs (a "pharmacological dissection"), yet decades of work have not localized a primary serotonergic lesion. This leaves the mechanism by which SRIs reduce obsessions and compulsions — and whether it is serotonergic at all rather than downstream CSTC-circuit remodeling — unresolved.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"The preferential efficacy of SRIs in OCD has neither led to discovery of serotonergic abnormalities in OCD nor to development of new serotonergic medications for OCD."
A leading review states explicitly that SRI efficacy has not been reconciled with any identified serotonergic abnormality, defining the gap.
Do rodent compulsive-grooming knockout models (Sapap3, Slitrk5, Slc1a1) faithfully model human OCD, given that they reproduce repetitive compulsive-like motor behavior but cannot capture the intrusive obsessions, symptom dimensions, and fluctuating insight that define the human disorder?
HUMAN MODEL MISMATCH OPEN mismatch_ocd_animal_models_obsessions
Attached to
genetic#SLITRK5 genetic#DLGAP3 genetic#SLC1A1 pathophysiology#Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
The strongest mechanistic evidence for cortico-striatal causation in OCD comes from mouse knockouts that develop excessive grooming reversible by SSRIs. However, grooming is a motor stereotypy; obsessions are cognitive-affective phenomena with no clear rodent analog, and insight is uniquely human. Whether these models inform the obsessional/cognitive core of OCD — or only its compulsive motor output — is mechanistically consequential for target validation.
Proposed experiments
Cross-species CSTC circuit readout alignment
exp_ocd_cross_species_cstc_alignment
Map orbitofrontal-striatal activity signatures associated with compulsive grooming in Sapap3/Slitrk5 mice onto task-based fMRI CSTC signatures in human OCD to test whether the same circuit state underlies rodent compulsions and human symptoms, distinguishing shared compulsive circuitry from human-specific obsessional processing.
Show evidence (1 reference)
PMID:20418887 SUPPORT Model Organism
"provide a new mouse model of OCD-like behaviors"
The model is explicitly described as reproducing OCD-"like" behaviors, underscoring that it captures a behavioral analog rather than the full human syndrome.

Pathophysiology

5
Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
OCD is associated with hyperactivity within cortico-striato-thalamo-cortical (CSTC) loops, particularly involving the orbitofrontal cortex, anterior cingulate cortex, caudate nucleus, and thalamus. Imbalance between the direct ("go") and indirect ("stop") basal ganglia pathways is thought to impair the ability to suppress intrusive thoughts and repetitive behaviors.
neuron CL:0000540
orbitofrontal cortex UBERON:0004167 anterior cingulate cortex UBERON:0009835 caudate nucleus UBERON:0001873 thalamus UBERON:0001897
Show evidence (3 references)
PMID:33384007 SUPPORT Human Clinical
"Functional imaging studies in OCD show consistent evidence for increased activity in brain regions that form a cortico-striato-thalamo-cortical (CSTC) loop."
Functional imaging evidence directly supports CSTC-loop hyperactivity as the core circuit-level abnormality in OCD.
PMID:37137502 SUPPORT Other
"We show how dysfunction in cortico-striato-thalamo-cortical (CSTC) circuits may underpin symptoms"
Review attributes OCD symptoms to CSTC circuit dysfunction.
PMID:17713528 SUPPORT Model Organism
"These findings demonstrate a critical role for SAPAP3 at cortico-striatal synapses and emphasize the importance of cortico-striatal circuitry in OCD-like behaviours."
Genetic disruption of the cortico-striatal scaffolding protein SAPAP3 in mice produces OCD-like behavior, providing causal support for cortico-striatal circuit involvement.
Dopaminergic Striatal Signaling
Dopaminergic signaling, particularly within the striatum, is implicated in OCD pathophysiology and in modulating compulsive behaviors. GWAS cell-type enrichment associates D1- and D2-receptor-containing striatal medium spiny neurons with OCD genetic risk.
dopamine receptor signaling pathway GO:0007212 ⚠ ABNORMAL
striatum UBERON:0002435
Show evidence (2 references)
PMID:37137502 SUPPORT Other
"shed light on the putative neurochemistry within these loops such as the role of serotonin, dopamine, and glutamate systems"
Review implicates dopamine (alongside serotonin and glutamate) in the neurochemistry of CSTC loops in OCD.
PMID:40360802 PARTIAL Human Clinical
"OCD genetic risk was associated with excitatory neurons in the hippocampus and the cortex, along with D1 and D2 type dopamine receptor-containing medium spiny neurons."
GWAS cell-type enrichment associates OCD genetic risk with dopaminergic striatal medium spiny neurons; this is genetic-association evidence rather than direct proof of dopaminergic causation.
Serotonergic Neurotransmission Dysregulation
Dysfunction of serotonergic signaling is implicated in OCD, supported by the selective efficacy of serotonin reuptake inhibitors. Altered serotonin receptor and transporter function modulates CSTC circuit activity.
serotonin receptor signaling pathway GO:0007210 ⚠ ABNORMAL
Show evidence (2 references)
PMID:37137502 SUPPORT Other
"shed light on the putative neurochemistry within these loops such as the role of serotonin, dopamine, and glutamate systems"
Review implicates serotonin (alongside dopamine and glutamate) in the neurochemistry of CSTC loops in OCD.
PMID:33384007 PARTIAL Human Clinical
"The preferential efficacy of SRIs in OCD has neither led to discovery of serotonergic abnormalities in OCD nor to development of new serotonergic medications for OCD."
The selective efficacy of serotonin reuptake inhibitors implicates the serotonin system, though direct serotonergic abnormalities remain unproven — supporting serotonergic involvement only partially.
Glutamatergic Signaling Imbalance
Elevated glutamatergic neurotransmission within CSTC circuits, including altered glutamate transporter (SLC1A1/EAAT3) function, contributes to excitatory imbalance in OCD.
glutamate receptor signaling pathway GO:0007215 ↑ INCREASED
Show evidence (2 references)
PMID:33384007 SUPPORT Human Clinical
"Several lines of preclinical and clinical evidence suggest dysfunction of the glutamatergic system in OCD, prompting testing of several promising glutamate modulating agents."
Preclinical and clinical evidence supports glutamatergic dysfunction as a contributor to OCD pathophysiology.
PMID:28507136 SUPPORT Model Organism
"these findings indicate that the most consistently associated OCD candidate gene impacts basal ganglia-dependent repetitive behaviors"
Disruption of the glutamate transporter gene Slc1a1/EAAT3 in mice alters basal ganglia function and repetitive behavior, linking glutamatergic transport to OCD-relevant circuitry.
Impaired Inhibitory Control and Habit Formation
The convergence of circuit and neurotransmitter abnormalities manifests as impaired top-down inhibitory control and a shift toward inflexible, habit-driven behavior, producing the obsessions and compulsions that characterize OCD. Cognitive deficits in response inhibition, cognitive flexibility, and goal-directed behavior are linked to aberrant CSTC activity.
neuron CL:0000540
regulation of behavior GO:0050795 ⚠ ABNORMAL
Show evidence (1 reference)
PMID:37137502 SUPPORT Other
"OCD is characterized by cognitive dysfunction including problems in cognitive flexibility, visuospatial memory, response inhibition, and goal-directed behavior, linked to aberrant activity within CSTC circuits"
Impaired response inhibition, cognitive flexibility, and goal-directed behavior are tied to aberrant CSTC activity, supporting this node as the behavioral output of circuit dysfunction.

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Obsessive-Compulsive Disorder Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.

Phenotypes

5
Nervous System 3
Compulsions Compulsive behaviors HP:0000722
Show evidence (1 reference)
PMID:37859440 SUPPORT Other
"characterized by overwhelming obsessions and compulsions"
Clinical review of human OCD identifies compulsions as a defining feature.
Anxiety Anxiety HP:0000739
Show evidence (2 references)
PMID:40360802 PARTIAL Human Clinical
"OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome"
Shared genetic risk between OCD and anxiety supports the close relationship of anxiety with OCD; this is genetic-correlation evidence rather than a direct measure of the anxiety phenotype.
PMID:20418887 SUPPORT Model Organism
"loss of a neuron-specific transmembrane protein, SLIT and NTRK-like protein-5 (Slitrk5), leads to OCD-like behaviors in mice, which manifests as excessive self-grooming and increased anxiety-like behaviors, and is alleviated by the selective serotonin reuptake inhibitor fluoxetine"
The Slitrk5 OCD mouse model recapitulates increased anxiety-like behavior alongside compulsive grooming.
Cognitive dysfunction Cognitive impairment HP:0100543
Show evidence (1 reference)
PMID:37137502 SUPPORT Other
"OCD is characterized by cognitive dysfunction including problems in cognitive flexibility, visuospatial memory, response inhibition, and goal-directed behavior, linked to aberrant activity within CSTC circuits"
Review documents OCD-associated cognitive dysfunction across multiple executive domains.
Other 2
Obsessions Obsessive-compulsive trait HP:0008770
Show evidence (1 reference)
PMID:37859440 SUPPORT Other
"characterized by overwhelming obsessions and compulsions"
Clinical review of human OCD identifies obsessions as a defining feature.
Impulsivity Impulsivity HP:0100710
Show evidence (1 reference)
PMID:33146050 PARTIAL Human Clinical
"Attentional impulsivity is associated with hoarding symptoms in OCD."
Study of 136 individuals with OCD links attentional impulsivity to the hoarding dimension; supports impulsivity as a feature in a subset of OCD.
🧬

Genetic Associations

7
Polygenic Risk (Risk Factor)
Show evidence (2 references)
PMID:40360802 SUPPORT Human Clinical
"We conducted a genome-wide association study (GWAS) meta-analysis combining 53,660 OCD cases and 2,044,417 controls and identified 30 independent genome-wide significant loci."
Large GWAS meta-analysis establishes the polygenic genetic architecture of OCD with 30 risk loci.
PMID:40360802 SUPPORT Human Clinical
"OCD genetic risk was associated with excitatory neurons in the hippocampus and the cortex, along with D1 and D2 type dopamine receptor-containing medium spiny neurons."
GWAS cell-type enrichment links OCD genetic risk to cortical excitatory neurons and striatal dopaminergic medium spiny neurons, consistent with the CSTC model.
WDR6 (Risk Factor)
Gene: WDR6 hgnc:12758
Show evidence (1 reference)
PMID:40360802 SUPPORT Human Clinical
"with 25 of these classified as the most likely causal candidates, including WDR6, DALRD3 and CTNND1"
WDR6 is named among the most likely causal OCD effector genes in the largest GWAS to date.
DALRD3 (Risk Factor)
Gene: DALRD3 hgnc:25536
Show evidence (1 reference)
PMID:40360802 SUPPORT Human Clinical
"with 25 of these classified as the most likely causal candidates, including WDR6, DALRD3 and CTNND1"
DALRD3 is named among the most likely causal OCD effector genes in the largest GWAS to date.
CTNND1 (Risk Factor)
Gene: CTNND1 hgnc:2515
Show evidence (1 reference)
PMID:40360802 SUPPORT Human Clinical
"with 25 of these classified as the most likely causal candidates, including WDR6, DALRD3 and CTNND1"
CTNND1 is named among the most likely causal OCD effector genes in the largest GWAS to date.
SLC1A1 (Risk Factor)
Gene: SLC1A1 hgnc:10939
Show evidence (1 reference)
PMID:28507136 SUPPORT Model Organism
"these findings indicate that the most consistently associated OCD candidate gene impacts basal ganglia-dependent repetitive behaviors"
SLC1A1/EAAT3 is described as the most consistently associated OCD candidate gene; its disruption in mice alters basal ganglia-dependent repetitive behavior.
SLITRK5 (Risk Factor)
Gene: SLITRK5 hgnc:20295
Show evidence (1 reference)
PMID:20418887 SUPPORT Model Organism
"loss of a neuron-specific transmembrane protein, SLIT and NTRK-like protein-5 (Slitrk5), leads to OCD-like behaviors in mice, which manifests as excessive self-grooming and increased anxiety-like behaviors, and is alleviated by the selective serotonin reuptake inhibitor fluoxetine"
Slitrk5 loss in mice produces OCD-like compulsive grooming and anxiety that responds to an SSRI, implicating the gene in corticostriatal OCD pathophysiology.
DLGAP3 (Risk Factor)
Gene: DLGAP3 (SAPAP3) hgnc:30368
Show evidence (1 reference)
PMID:17713528 SUPPORT Model Organism
"mice with genetic deletion of Sapap3 exhibit increased anxiety and compulsive grooming behaviour leading to facial hair loss and skin lesions; both behaviours are alleviated by a selective serotonin reuptake inhibitor"
Sapap3 (DLGAP3) deletion in mice recapitulates OCD-like compulsive grooming and anxiety responsive to an SSRI, implicating cortico-striatal synaptic dysfunction.
💊

Medical Actions

6
Selective Serotonin Reuptake Inhibitors
Action: Pharmacotherapy NCIT:C15986
Agent: fluoxetine CHEBI:5118 sertraline CHEBI:9123
SSRIs (e.g., fluoxetine, sertraline, fluvoxamine, paroxetine) are first-line pharmacotherapy for OCD, typically requiring higher doses and longer duration than for depression.
Mechanism Target:
MODULATES Serotonergic Neurotransmission Dysregulation — SSRIs block presynaptic serotonin reuptake, increasing synaptic serotonin and modulating serotonergic signaling within CSTC circuits.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"The only established first-line treatments for OCD are exposure and response prevention, and serotonin reuptake inhibitor medications (SRIs)."
Serotonin reuptake inhibitors are an established first-line pharmacotherapy for OCD.
Cognitive Behavioral Therapy with Exposure and Response Prevention
Action: cognitive behavior therapy MAXO:0000883
CBT incorporating exposure and response prevention (ERP) is a first-line psychotherapeutic treatment for OCD.
Mechanism Target:
MODULATES Impaired Inhibitory Control and Habit Formation — Exposure and response prevention promotes inhibitory learning and fear extinction, strengthening behavioral control over compulsions at the behavioral output of CSTC dysfunction.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"The only established first-line treatments for OCD are exposure and response prevention, and serotonin reuptake inhibitor medications (SRIs)."
Exposure and response prevention is an established first-line treatment for OCD.
Antipsychotic Augmentation
Action: Pharmacotherapy NCIT:C15986
Agent: risperidone CHEBI:8871 aripiprazole CHEBI:31236
Adjunctive low-dose antipsychotic agents (e.g., risperidone, aripiprazole) are added to serotonin reuptake inhibitors in partial responders, and are the medication augmentation approach with the strongest empirical support in OCD.
Mechanism Target:
MODULATES Dopaminergic Striatal Signaling — Antipsychotic augmentation modulates dopamine (D2) receptor signaling in the striatum to reduce persistent compulsivity in SRI partial responders.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"Beyond SRI monotherapy, antipsychotic augmentation is the only medication approach for OCD with substantial empirical support."
Antipsychotic augmentation of SRIs is the best-supported pharmacological augmentation strategy for OCD.
Deep Brain Stimulation
Action: deep brain stimulation MAXO:0000943
Deep brain stimulation targeting nodes of the CSTC circuit is used for severe, treatment-refractory OCD, providing further support for the CSTC model.
Mechanism Target:
MODULATES Cortico-Striato-Thalamo-Cortical Circuit Dysfunction — DBS delivers electrical modulation to CSTC nodes (e.g., ventral capsule/ventral striatum), rebalancing pathologic frontostriatal network activity.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"Neuromodulation treatments with either noninvasive devices (e.g., transcranial magnetic stimulation) or invasive procedures (e.g., deep brain stimulation) provide further support for the CSTC model of OCD."
Deep brain stimulation is an established neuromodulation treatment for refractory OCD that targets the CSTC circuit.
Transcranial Magnetic Stimulation
Action: transcranial magnetic stimulation Ontology label: Transcranial Magnetic Stimulation NCIT:C116655
Repetitive/deep transcranial magnetic stimulation (TMS) is a noninvasive neuromodulation therapy, FDA-cleared for OCD, that targets medial prefrontal/anterior cingulate nodes of the CSTC circuit.
Mechanism Target:
MODULATES Cortico-Striato-Thalamo-Cortical Circuit Dysfunction — TMS noninvasively modulates dysfunctional frontostriatal/CSTC activity.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"Neuromodulation treatments with either noninvasive devices (e.g., transcranial magnetic stimulation) or invasive procedures (e.g., deep brain stimulation) provide further support for the CSTC model of OCD."
Transcranial magnetic stimulation is a noninvasive neuromodulation treatment for OCD targeting the CSTC circuit.
Clomipramine
Action: Pharmacotherapy NCIT:C15986
Agent: clomipramine CHEBI:47780
Clomipramine, a serotonin-predominant tricyclic, was the first medication proven effective in OCD and remains a potent serotonin reuptake inhibitor option, typically reserved for SSRI non-responders due to its side-effect profile.
Mechanism Target:
MODULATES Serotonergic Neurotransmission Dysregulation — Clomipramine potently inhibits serotonin reuptake, modulating serotonergic signaling within CSTC circuits.
Show evidence (1 reference)
PMID:33384007 SUPPORT Human Clinical
"The only established first-line treatments for OCD are exposure and response prevention, and serotonin reuptake inhibitor medications (SRIs)."
Clomipramine is a serotonin reuptake inhibitor, the established pharmacological class for OCD.
🌍

Environmental Factors

1
Streptococcal infection (PANDAS)
In a subset of children, group A streptococcal infection is associated with the abrupt onset of obsessive-compulsive symptoms and/or tics (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, PANDAS), proposed to reflect an autoimmune/neuroinflammatory mechanism. The diagnosis remains controversial.
Show evidence (1 reference)
PMID:34778136 SUPPORT Human Clinical
"are clinical conditions characterized by the sudden onset of obsessive-compulsive disorder and/or tics"
PANDAS links streptococcal infection to acute-onset OCD in a subset of children, an environmental/immune trigger.
🔀

Differential Diagnoses

5

Conditions with similar clinical presentations that must be differentiated from Obsessive-Compulsive Disorder:

Overlapping Features An obsessive-compulsive and related disorder featuring preoccupation with perceived physical defects and related repetitive behaviors.
Distinguishing Features
  • Preoccupations focus specifically on perceived appearance defects rather than broader obsessional themes.
Show evidence (1 reference)
PMID:37859440 SUPPORT Other
"removed OCD from the anxiety disorder grouping and regrouped it into obsessive-compulsive and related disorders"
Body dysmorphic disorder is part of the obsessive-compulsive and related disorders spectrum distinguished from OCD.
Trichotillomania Not Yet Curated MONDO:0013189
Overlapping Features A body-focused repetitive behavior disorder (hair-pulling) within the obsessive-compulsive and related disorders spectrum.
Distinguishing Features
  • Repetitive hair-pulling is not driven by obsessions and is typically not anxiety-reducing in the OCD sense.
Show evidence (1 reference)
PMID:37859440 SUPPORT Other
"removed OCD from the anxiety disorder grouping and regrouped it into obsessive-compulsive and related disorders"
Trichotillomania is part of the obsessive-compulsive and related disorders spectrum distinguished from OCD.
Overlapping Features A tic disorder that frequently co-occurs with OCD and shares genetic risk, but is defined by motor and vocal tics rather than obsessions/compulsions.
Distinguishing Features
  • Defined by involuntary motor/vocal tics rather than obsession-driven compulsions.
Show evidence (1 reference)
PMID:40360802 SUPPORT Human Clinical
"OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome"
OCD shares genetic risk with Tourette syndrome, a key differential and comorbidity.
Overlapping Features A differential characterized by pervasive, excessive worry about everyday matters rather than discrete intrusive obsessions and ritualized compulsions.
Distinguishing Features
  • Worries are about realistic life concerns and are not neutralized by compulsive rituals.
Show evidence (1 reference)
PMID:40360802 PARTIAL Human Clinical
"OCD shared genetic risk with anxiety, depression, anorexia nervosa and Tourette syndrome"
OCD shares genetic liability with anxiety disorders, a frequent differential; the snippet supports the shared-risk relationship.
Obsessive-compulsive personality disorder Not Yet Curated MONDO:0001158
Overlapping Features A personality disorder of perfectionism, orderliness, and control that is ego-syntonic, distinct from the ego-dystonic obsessions and compulsions of OCD.
Distinguishing Features
  • Traits are ego-syntonic (experienced as appropriate) rather than ego-dystonic intrusive obsessions.
🔬

Clinical Trials

3
NCT03299166 PHASE_III COMPLETED
Randomized, double-blind, placebo-controlled Phase 2/3 trial of adjunctive troriluzole (a glutamate-modulating prodrug of riluzole) in adults with OCD and inadequate response to serotonergic pharmacotherapy, testing the glutamatergic-dysregulation hypothesis therapeutically.
Target Phenotypes: Obsessions and compulsions HP:0008770
Show evidence (1 reference)
clinicaltrials:NCT03299166 SUPPORT Human Clinical
"The purpose of this study is to evaluate the efficacy of troriluzole as adjunctive therapy versus placebo in participants with obsessive compulsive disorder (OCD) who had an inadequate response to selective serotonin reuptake inhibitor (SSRI), clomipramine, venlafaxine, or desvenlafaxine treatment"
Trial of an adjunctive glutamate modulator directly tests the glutamatergic-imbalance mechanism in treatment-resistant OCD.
NCT02229903 NOT_APPLICABLE COMPLETED
Randomized, double-blind, multicenter, sham-controlled trial of deep transcranial magnetic stimulation (dTMS) over medial prefrontal/anterior cingulate cortex in OCD; the pivotal study supporting FDA clearance of dTMS for OCD and a clinical test of the CSTC neuromodulation model.
Target Phenotypes: Obsessions and compulsions HP:0008770
Show evidence (1 reference)
clinicaltrials:NCT02229903 SUPPORT Human Clinical
"The Brainsway DTMS study is a randomized, 10 week, double blind, multi-center trial comparing active DTMS treatment to sham treatment."
Sham-controlled multicenter dTMS trial tests CSTC-targeted neuromodulation as a treatment for OCD.
NCT03356483 PHASE_I COMPLETED
Double-blind, placebo-controlled study of oral psilocybin in OCD, probing serotonergic (5-HT2A) psychedelic modulation of OCD symptoms and its neural correlates.
Target Phenotypes: Obsessions and compulsions HP:0008770
Show evidence (1 reference)
clinicaltrials:NCT03356483 SUPPORT Human Clinical
"This study aims to investigate the effects of oral psilocybin on OCD symptomatology and provide the first evidence of the neural mechanism that may mediate psilocybin's purported therapeutic effects on OCD."
Psilocybin trial tests serotonergic 5-HT2A modulation as a novel mechanism-based treatment for OCD.
{ }

Source YAML

click to show
name: Obsessive-Compulsive Disorder
creation_date: "2026-06-21T00:00:00Z"
category: Psychiatric
description: >-
  Obsessive-compulsive disorder (OCD) is a chronic psychiatric disorder
  characterized by persistent, intrusive, and distressing thoughts, images, or
  urges (obsessions) and repetitive behaviors or mental acts (compulsions)
  performed to reduce the anxiety the obsessions provoke. The pathophysiology
  centers on dysfunction of cortico-striato-thalamo-cortical (CSTC) circuits,
  with contributions from serotonergic, glutamatergic, and dopaminergic
  neurotransmission. OCD affects roughly 1-3% of the population, typically
  begins in childhood or early adulthood, and follows a chronic course. In
  DSM-5 and ICD-11 it was moved out of the anxiety disorders into the new
  "obsessive-compulsive and related disorders" grouping, although MONDO still
  classifies it under anxiety disorder.
disease_term:
  preferred_term: obsessive-compulsive disorder
  term:
    id: MONDO:0008114
    label: obsessive-compulsive disorder
parents:
- Anxiety Disorder
- Mental Health Disorder
pathophysiology:
- name: Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
  description: >-
    OCD is associated with hyperactivity within cortico-striato-thalamo-cortical
    (CSTC) loops, particularly involving the orbitofrontal cortex, anterior
    cingulate cortex, caudate nucleus, and thalamus. Imbalance between the
    direct ("go") and indirect ("stop") basal ganglia pathways is thought to
    impair the ability to suppress intrusive thoughts and repetitive behaviors.
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  locations:
  - preferred_term: orbitofrontal cortex
    term:
      id: UBERON:0004167
      label: orbitofrontal cortex
  - preferred_term: anterior cingulate cortex
    term:
      id: UBERON:0009835
      label: anterior cingulate cortex
  - preferred_term: caudate nucleus
    term:
      id: UBERON:0001873
      label: caudate nucleus
  - preferred_term: thalamus
    term:
      id: UBERON:0001897
      label: dorsal plus ventral thalamus
  downstream:
  - target: Impaired Inhibitory Control and Habit Formation
    description: >-
      CSTC hyperactivity is modeled upstream of impaired behavioral inhibition
      and pathological habit formation.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Functional imaging studies in OCD show consistent evidence for increased
      activity in brain regions that form a cortico-striato-thalamo-cortical
      (CSTC) loop.
    explanation: >-
      Functional imaging evidence directly supports CSTC-loop hyperactivity as
      the core circuit-level abnormality in OCD.
  - reference: PMID:37137502
    reference_title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      We show how dysfunction in cortico-striato-thalamo-cortical (CSTC)
      circuits may underpin symptoms
    explanation: >-
      Review attributes OCD symptoms to CSTC circuit dysfunction.
  - reference: PMID:17713528
    reference_title: "Cortico-striatal synaptic defects and OCD-like behaviours in Sapap3-mutant mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      These findings demonstrate a critical role for SAPAP3 at cortico-striatal
      synapses and emphasize the importance of cortico-striatal circuitry in
      OCD-like behaviours.
    explanation: >-
      Genetic disruption of the cortico-striatal scaffolding protein SAPAP3 in
      mice produces OCD-like behavior, providing causal support for
      cortico-striatal circuit involvement.
- name: Dopaminergic Striatal Signaling
  description: >-
    Dopaminergic signaling, particularly within the striatum, is implicated in
    OCD pathophysiology and in modulating compulsive behaviors. GWAS cell-type
    enrichment associates D1- and D2-receptor-containing striatal medium spiny
    neurons with OCD genetic risk.
  biological_processes:
  - preferred_term: dopamine receptor signaling pathway
    term:
      id: GO:0007212
      label: G protein-coupled dopamine receptor signaling pathway
    modifier: ABNORMAL
  locations:
  - preferred_term: striatum
    term:
      id: UBERON:0002435
      label: striatum
  downstream:
  - target: Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
    description: >-
      Dopaminergic striatal signaling is represented upstream of circuit-level
      dysfunction.
  evidence:
  - reference: PMID:37137502
    reference_title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      shed light on the putative neurochemistry within these loops such as the
      role of serotonin, dopamine, and glutamate systems
    explanation: >-
      Review implicates dopamine (alongside serotonin and glutamate) in the
      neurochemistry of CSTC loops in OCD.
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD genetic risk was associated with excitatory neurons in the
      hippocampus and the cortex, along with D1 and D2 type dopamine
      receptor-containing medium spiny neurons.
    explanation: >-
      GWAS cell-type enrichment associates OCD genetic risk with dopaminergic
      striatal medium spiny neurons; this is genetic-association evidence rather
      than direct proof of dopaminergic causation.
- name: Serotonergic Neurotransmission Dysregulation
  description: >-
    Dysfunction of serotonergic signaling is implicated in OCD, supported by the
    selective efficacy of serotonin reuptake inhibitors. Altered serotonin
    receptor and transporter function modulates CSTC circuit activity.
  biological_processes:
  - preferred_term: serotonin receptor signaling pathway
    term:
      id: GO:0007210
      label: serotonin receptor signaling pathway
    modifier: ABNORMAL
  downstream:
  - target: Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
    description: >-
      Serotonergic dysregulation is represented upstream of circuit-level
      dysfunction.
  evidence:
  - reference: PMID:37137502
    reference_title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      shed light on the putative neurochemistry within these loops such as the
      role of serotonin, dopamine, and glutamate systems
    explanation: >-
      Review implicates serotonin (alongside dopamine and glutamate) in the
      neurochemistry of CSTC loops in OCD.
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The preferential efficacy of SRIs in OCD has neither led to discovery of
      serotonergic abnormalities in OCD nor to development of new serotonergic
      medications for OCD.
    explanation: >-
      The selective efficacy of serotonin reuptake inhibitors implicates the
      serotonin system, though direct serotonergic abnormalities remain
      unproven — supporting serotonergic involvement only partially.
- name: Glutamatergic Signaling Imbalance
  description: >-
    Elevated glutamatergic neurotransmission within CSTC circuits, including
    altered glutamate transporter (SLC1A1/EAAT3) function, contributes to
    excitatory imbalance in OCD.
  biological_processes:
  - preferred_term: glutamate receptor signaling pathway
    term:
      id: GO:0007215
      label: glutamate receptor signaling pathway
    modifier: INCREASED
  downstream:
  - target: Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
    description: >-
      Glutamatergic imbalance is represented upstream of circuit-level
      dysfunction.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Several lines of preclinical and clinical evidence suggest dysfunction of
      the glutamatergic system in OCD, prompting testing of several promising
      glutamate modulating agents.
    explanation: >-
      Preclinical and clinical evidence supports glutamatergic dysfunction as a
      contributor to OCD pathophysiology.
  - reference: PMID:28507136
    reference_title: "OCD candidate gene SLC1A1/EAAT3 impacts basal ganglia-mediated activity and stereotypic behavior"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      these findings indicate that the most consistently associated OCD
      candidate gene impacts basal ganglia-dependent repetitive behaviors
    explanation: >-
      Disruption of the glutamate transporter gene Slc1a1/EAAT3 in mice alters
      basal ganglia function and repetitive behavior, linking glutamatergic
      transport to OCD-relevant circuitry.
- name: Impaired Inhibitory Control and Habit Formation
  description: >-
    The convergence of circuit and neurotransmitter abnormalities manifests as
    impaired top-down inhibitory control and a shift toward inflexible,
    habit-driven behavior, producing the obsessions and compulsions that
    characterize OCD. Cognitive deficits in response inhibition, cognitive
    flexibility, and goal-directed behavior are linked to aberrant CSTC
    activity.
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: regulation of behavior
    term:
      id: GO:0050795
      label: regulation of behavior
    modifier: ABNORMAL
  evidence:
  - reference: PMID:37137502
    reference_title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      OCD is characterized by cognitive dysfunction including problems in
      cognitive flexibility, visuospatial memory, response inhibition, and
      goal-directed behavior, linked to aberrant activity within CSTC circuits
    explanation: >-
      Impaired response inhibition, cognitive flexibility, and goal-directed
      behavior are tied to aberrant CSTC activity, supporting this node as the
      behavioral output of circuit dysfunction.
phenotypes:
- name: Obsessions
  description: >-
    Recurrent, persistent, intrusive thoughts, urges, or images that are
    experienced as unwanted and that cause marked anxiety or distress.
  phenotype_term:
    preferred_term: Obsessions
    term:
      id: HP:0008770
      label: Obsessive-compulsive trait
  evidence:
  - reference: PMID:37859440
    reference_title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      characterized by overwhelming obsessions and compulsions
    explanation: >-
      Clinical review of human OCD identifies obsessions as a defining feature.
- name: Compulsions
  description: >-
    Repetitive behaviors or mental acts that the individual feels driven to
    perform in response to an obsession or according to rigid rules, aimed at
    reducing anxiety or preventing a dreaded event.
  phenotype_term:
    preferred_term: Compulsions
    term:
      id: HP:0000722
      label: Compulsive behaviors
  evidence:
  - reference: PMID:37859440
    reference_title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      characterized by overwhelming obsessions and compulsions
    explanation: >-
      Clinical review of human OCD identifies compulsions as a defining feature.
- name: Anxiety
  description: >-
    Marked anxiety and distress provoked by obsessions and by resisting
    compulsions.
  phenotype_term:
    preferred_term: Anxiety
    term:
      id: HP:0000739
      label: Anxiety
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD shared genetic risk with anxiety, depression, anorexia nervosa and
      Tourette syndrome
    explanation: >-
      Shared genetic risk between OCD and anxiety supports the close
      relationship of anxiety with OCD; this is genetic-correlation evidence
      rather than a direct measure of the anxiety phenotype.
  - reference: PMID:20418887
    reference_title: "Slitrk5 deficiency impairs corticostriatal circuitry and leads to obsessive-compulsive-like behaviors in mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      loss of a neuron-specific transmembrane protein, SLIT and NTRK-like
      protein-5 (Slitrk5), leads to OCD-like behaviors in mice, which manifests
      as excessive self-grooming and increased anxiety-like behaviors, and is
      alleviated by the selective serotonin reuptake inhibitor fluoxetine
    explanation: >-
      The Slitrk5 OCD mouse model recapitulates increased anxiety-like behavior
      alongside compulsive grooming.
- name: Cognitive dysfunction
  category: Cognitive
  description: >-
    OCD is associated with cognitive deficits including impaired response
    inhibition, reduced cognitive flexibility, and impaired goal-directed
    behavior, linked to aberrant CSTC circuit activity.
  phenotype_term:
    preferred_term: Cognitive impairment
    term:
      id: HP:0100543
      label: Cognitive impairment
  evidence:
  - reference: PMID:37137502
    reference_title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      OCD is characterized by cognitive dysfunction including problems in
      cognitive flexibility, visuospatial memory, response inhibition, and
      goal-directed behavior, linked to aberrant activity within CSTC circuits
    explanation: >-
      Review documents OCD-associated cognitive dysfunction across multiple
      executive domains.
- name: Impulsivity
  category: Behavioral
  description: >-
    Impulsivity, particularly attentional impulsivity, is elevated in OCD and is
    associated with the hoarding symptom dimension, reflecting overlap between
    compulsive and impulsive features.
  phenotype_term:
    preferred_term: Impulsivity
    term:
      id: HP:0100710
      label: Impulsivity
  evidence:
  - reference: PMID:33146050
    reference_title: "Multifaceted impulsivity in obsessive-compulsive disorder with hoarding symptoms"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Attentional impulsivity is associated with hoarding symptoms in OCD.
    explanation: >-
      Study of 136 individuals with OCD links attentional impulsivity to the
      hoarding dimension; supports impulsivity as a feature in a subset of OCD.
genetic:
- name: Polygenic Risk
  association: Risk Factor
  notes: >-
    OCD is a heritable, polygenic disorder. A 2025 GWAS meta-analysis of 53,660
    cases and 2,044,417 controls identified 30 independent genome-wide
    significant loci and implicated excitatory neurons and dopaminergic medium
    spiny neurons in genetic risk.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We conducted a genome-wide association study (GWAS) meta-analysis
      combining 53,660 OCD cases and 2,044,417 controls and identified 30
      independent genome-wide significant loci.
    explanation: >-
      Large GWAS meta-analysis establishes the polygenic genetic architecture
      of OCD with 30 risk loci.
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD genetic risk was associated with excitatory neurons in the
      hippocampus and the cortex, along with D1 and D2 type dopamine
      receptor-containing medium spiny neurons.
    explanation: >-
      GWAS cell-type enrichment links OCD genetic risk to cortical excitatory
      neurons and striatal dopaminergic medium spiny neurons, consistent with
      the CSTC model.
- name: WDR6
  gene_term:
    preferred_term: WDR6
    term:
      id: hgnc:12758
      label: WDR6
  association: Risk Factor
  notes: >-
    WD repeat domain 6 (2q33); one of the most likely causal effector genes from
    the 2025 OCD GWAS, prioritized by both TWAS-COLOC and SMR-HEIDI causal-support
    filters.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      with 25 of these classified as the most likely causal candidates,
      including WDR6, DALRD3 and CTNND1
    explanation: >-
      WDR6 is named among the most likely causal OCD effector genes in the
      largest GWAS to date.
- name: DALRD3
  gene_term:
    preferred_term: DALRD3
    term:
      id: hgnc:25536
      label: DALRD3
  association: Risk Factor
  notes: >-
    DALR anticodon binding domain-containing 3 (2q33); prioritized as a likely
    causal OCD effector gene by convergent causal-inference methods in the 2025
    GWAS.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      with 25 of these classified as the most likely causal candidates,
      including WDR6, DALRD3 and CTNND1
    explanation: >-
      DALRD3 is named among the most likely causal OCD effector genes in the
      largest GWAS to date.
- name: CTNND1
  gene_term:
    preferred_term: CTNND1
    term:
      id: hgnc:2515
      label: CTNND1
  association: Risk Factor
  notes: >-
    Catenin delta-1 (6p22), a synaptic adhesion-related gene; implicated by
    three orthogonal approaches (mBAT-combo, TWAS, PWAS) with colocalization
    evidence, including protein downregulation in prefrontal cortex associated
    with OCD risk.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      with 25 of these classified as the most likely causal candidates,
      including WDR6, DALRD3 and CTNND1
    explanation: >-
      CTNND1 is named among the most likely causal OCD effector genes in the
      largest GWAS to date.
- name: SLC1A1
  gene_term:
    preferred_term: SLC1A1
    term:
      id: hgnc:10939
      label: SLC1A1
  association: Risk Factor
  notes: >-
    Encodes the neuronal glutamate transporter EAAT3; variants have been
    associated with OCD, implicating glutamatergic dysregulation in CSTC
    circuits.
  evidence:
  - reference: PMID:28507136
    reference_title: "OCD candidate gene SLC1A1/EAAT3 impacts basal ganglia-mediated activity and stereotypic behavior"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      these findings indicate that the most consistently associated OCD
      candidate gene impacts basal ganglia-dependent repetitive behaviors
    explanation: >-
      SLC1A1/EAAT3 is described as the most consistently associated OCD
      candidate gene; its disruption in mice alters basal ganglia-dependent
      repetitive behavior.
- name: SLITRK5
  gene_term:
    preferred_term: SLITRK5
    term:
      id: hgnc:20295
      label: SLITRK5
  association: Risk Factor
  notes: >-
    SLIT- and NTRK-like family member 5; Slitrk5-knockout mice display
    compulsive grooming and corticostriatal abnormalities, modeling OCD-like
    behavior.
  evidence:
  - reference: PMID:20418887
    reference_title: "Slitrk5 deficiency impairs corticostriatal circuitry and leads to obsessive-compulsive-like behaviors in mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      loss of a neuron-specific transmembrane protein, SLIT and NTRK-like
      protein-5 (Slitrk5), leads to OCD-like behaviors in mice, which manifests
      as excessive self-grooming and increased anxiety-like behaviors, and is
      alleviated by the selective serotonin reuptake inhibitor fluoxetine
    explanation: >-
      Slitrk5 loss in mice produces OCD-like compulsive grooming and anxiety
      that responds to an SSRI, implicating the gene in corticostriatal OCD
      pathophysiology.
- name: DLGAP3
  gene_term:
    preferred_term: DLGAP3 (SAPAP3)
    term:
      id: hgnc:30368
      label: DLGAP3
  association: Risk Factor
  notes: >-
    DLGAP3 encodes SAPAP3, a postsynaptic scaffolding protein at cortico-striatal
    excitatory synapses highly expressed in the striatum. Sapap3-knockout mice
    are a well-established model of OCD-like compulsive grooming.
  evidence:
  - reference: PMID:17713528
    reference_title: "Cortico-striatal synaptic defects and OCD-like behaviours in Sapap3-mutant mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      mice with genetic deletion of Sapap3 exhibit increased anxiety and
      compulsive grooming behaviour leading to facial hair loss and skin
      lesions; both behaviours are alleviated by a selective serotonin reuptake
      inhibitor
    explanation: >-
      Sapap3 (DLGAP3) deletion in mice recapitulates OCD-like compulsive
      grooming and anxiety responsive to an SSRI, implicating cortico-striatal
      synaptic dysfunction.
treatments:
- name: Selective Serotonin Reuptake Inhibitors
  description: >-
    SSRIs (e.g., fluoxetine, sertraline, fluvoxamine, paroxetine) are first-line
    pharmacotherapy for OCD, typically requiring higher doses and longer
    duration than for depression.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: fluoxetine
      term:
        id: CHEBI:5118
        label: fluoxetine
    - preferred_term: sertraline
      term:
        id: CHEBI:9123
        label: sertraline
  target_mechanisms:
  - target: Serotonergic Neurotransmission Dysregulation
    treatment_effect: MODULATES
    description: >-
      SSRIs block presynaptic serotonin reuptake, increasing synaptic serotonin
      and modulating serotonergic signaling within CSTC circuits.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The only established first-line treatments for OCD are exposure and
      response prevention, and serotonin reuptake inhibitor medications (SRIs).
    explanation: >-
      Serotonin reuptake inhibitors are an established first-line
      pharmacotherapy for OCD.
- name: Cognitive Behavioral Therapy with Exposure and Response Prevention
  description: >-
    CBT incorporating exposure and response prevention (ERP) is a first-line
    psychotherapeutic treatment for OCD.
  treatment_term:
    preferred_term: cognitive behavior therapy
    term:
      id: MAXO:0000883
      label: cognitive behavior therapy
  target_mechanisms:
  - target: Impaired Inhibitory Control and Habit Formation
    treatment_effect: MODULATES
    description: >-
      Exposure and response prevention promotes inhibitory learning and fear
      extinction, strengthening behavioral control over compulsions at the
      behavioral output of CSTC dysfunction.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The only established first-line treatments for OCD are exposure and
      response prevention, and serotonin reuptake inhibitor medications (SRIs).
    explanation: >-
      Exposure and response prevention is an established first-line treatment
      for OCD.
- name: Antipsychotic Augmentation
  description: >-
    Adjunctive low-dose antipsychotic agents (e.g., risperidone, aripiprazole)
    are added to serotonin reuptake inhibitors in partial responders, and are
    the medication augmentation approach with the strongest empirical support
    in OCD.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: risperidone
      term:
        id: CHEBI:8871
        label: risperidone
    - preferred_term: aripiprazole
      term:
        id: CHEBI:31236
        label: aripiprazole
  target_mechanisms:
  - target: Dopaminergic Striatal Signaling
    treatment_effect: MODULATES
    description: >-
      Antipsychotic augmentation modulates dopamine (D2) receptor signaling in
      the striatum to reduce persistent compulsivity in SRI partial responders.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Beyond SRI monotherapy, antipsychotic augmentation is the only medication
      approach for OCD with substantial empirical support.
    explanation: >-
      Antipsychotic augmentation of SRIs is the best-supported pharmacological
      augmentation strategy for OCD.
- name: Deep Brain Stimulation
  description: >-
    Deep brain stimulation targeting nodes of the CSTC circuit is used for
    severe, treatment-refractory OCD, providing further support for the CSTC
    model.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: deep brain stimulation
    term:
      id: MAXO:0000943
      label: deep brain stimulation
  target_mechanisms:
  - target: Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
    treatment_effect: MODULATES
    description: >-
      DBS delivers electrical modulation to CSTC nodes (e.g., ventral
      capsule/ventral striatum), rebalancing pathologic frontostriatal network
      activity.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neuromodulation treatments with either noninvasive devices (e.g.,
      transcranial magnetic stimulation) or invasive procedures (e.g., deep
      brain stimulation) provide further support for the CSTC model of OCD.
    explanation: >-
      Deep brain stimulation is an established neuromodulation treatment for
      refractory OCD that targets the CSTC circuit.
- name: Transcranial Magnetic Stimulation
  description: >-
    Repetitive/deep transcranial magnetic stimulation (TMS) is a noninvasive
    neuromodulation therapy, FDA-cleared for OCD, that targets medial
    prefrontal/anterior cingulate nodes of the CSTC circuit.
  therapeutic_modality: DEVICE
  treatment_term:
    preferred_term: transcranial magnetic stimulation
    term:
      id: NCIT:C116655
      label: Transcranial Magnetic Stimulation
  target_mechanisms:
  - target: Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
    treatment_effect: MODULATES
    description: >-
      TMS noninvasively modulates dysfunctional frontostriatal/CSTC activity.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Neuromodulation treatments with either noninvasive devices (e.g.,
      transcranial magnetic stimulation) or invasive procedures (e.g., deep
      brain stimulation) provide further support for the CSTC model of OCD.
    explanation: >-
      Transcranial magnetic stimulation is a noninvasive neuromodulation
      treatment for OCD targeting the CSTC circuit.
- name: Clomipramine
  description: >-
    Clomipramine, a serotonin-predominant tricyclic, was the first medication
    proven effective in OCD and remains a potent serotonin reuptake inhibitor
    option, typically reserved for SSRI non-responders due to its side-effect
    profile.
  therapeutic_modality: SMALL_MOLECULE
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: clomipramine
      term:
        id: CHEBI:47780
        label: clomipramine
  target_mechanisms:
  - target: Serotonergic Neurotransmission Dysregulation
    treatment_effect: MODULATES
    description: >-
      Clomipramine potently inhibits serotonin reuptake, modulating serotonergic
      signaling within CSTC circuits.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The only established first-line treatments for OCD are exposure and
      response prevention, and serotonin reuptake inhibitor medications (SRIs).
    explanation: >-
      Clomipramine is a serotonin reuptake inhibitor, the established
      pharmacological class for OCD.
synonyms:
- obsessive compulsive disorder
- OCD
classifications:
  harrisons_chapter:
  - classification_value: NEUROLOGIC
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0008114
      label: obsessive-compulsive disorder
    mapping_predicate: skos:exactMatch
    mapping_source: MONDO
    mapping_justification: Primary MONDO disease identifier for obsessive-compulsive disorder.
  icd10cm_mappings:
  - term:
      id: ICD10CM:F42
      label: Obsessive-compulsive disorder
    mapping_predicate: skos:exactMatch
    mapping_source: MONDO
    mapping_justification: MONDO cross-references ICD-10-CM F42 for obsessive-compulsive disorder.
  ncit_mappings:
  - term:
      id: NCIT:C88411
      label: Obsessive Compulsive Disorder
    mapping_predicate: skos:exactMatch
    mapping_source: MONDO
    mapping_justification: MONDO cross-references NCIT C88411 for obsessive-compulsive disorder.
prevalence:
- population: global (lifetime)
  measure_type: LIFETIME_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 4100.0
  percentage: 4.1
  notes: World Mental Health surveys across 10 countries; literature range 1-3%.
  evidence:
  - reference: PMID:40629326
    reference_title: "Obsessive-compulsive disorder in the World Mental Health surveys"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD has a combined lifetime prevalence of 4.1%. The 12-month prevalence
      (3.0%) is nearly as high
    explanation: >-
      Cross-national surveys establish OCD lifetime prevalence at 4.1%.
- population: global (12-month)
  measure_type: PERIOD_PREVALENCE
  prevalence_class: ABOVE_1_IN_1000
  rate_per_100000: 3000.0
  percentage: 3.0
  notes: Near-equal 12-month and lifetime prevalence indicates a highly persistent course.
  evidence:
  - reference: PMID:40629326
    reference_title: "Obsessive-compulsive disorder in the World Mental Health surveys"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD has a combined lifetime prevalence of 4.1%. The 12-month prevalence
      (3.0%) is nearly as high
    explanation: >-
      12-month prevalence (3.0%) nearly equals lifetime prevalence, reflecting
      chronicity.
epidemiology:
- name: Age of onset
  description: >-
    OCD onset is early, with more than 80% of cases beginning by early
    adulthood; onset is bimodal, peaking in adolescence and young adulthood.
  evidence:
  - reference: PMID:40629326
    reference_title: "Obsessive-compulsive disorder in the World Mental Health surveys"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Age of onset is early, with more than 80% of OCD cases beginning by early
      adulthood.
    explanation: >-
      Most OCD begins by early adulthood.
- name: Treatment gap
  description: >-
    OCD is widely undertreated; only about one in five affected individuals
    receives any past-year mental health treatment, with a large high- versus
    low/middle-income disparity.
  evidence:
  - reference: PMID:40629326
    reference_title: "Obsessive-compulsive disorder in the World Mental Health surveys"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Only 19.8% of respondents with OCD received any mental health treatment in
      the past year
    explanation: >-
      Quantifies the OCD treatment gap.
inheritance:
- name: Multifactorial (polygenic)
  inheritance_term:
    preferred_term: Polygenic inheritance
    term:
      id: HP:0010982
      label: Polygenic inheritance
  description: >-
    OCD is a heritable, highly polygenic disorder; twin heritability is roughly
    27-47% in adults and 45-65% in children, and common variants distributed
    across thousands of loci account for most of the SNP-based heritability.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We estimated that ~11,500 genetic variants explained 90% of OCD genetic
      heritability.
    explanation: >-
      Heritability distributed across ~11,500 variants establishes highly
      polygenic inheritance.
progression:
- phase: Onset
  age_range: 12-22
  notes: Bimodal onset peaking in adolescence (12-14) and young adulthood (20-22).
  evidence:
  - reference: PMID:37859440
    reference_title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      OCD typically starts in childhood or adolescence and persists throughout
      life
    explanation: >-
      OCD typically begins in childhood or adolescence.
- phase: Chronic course
  notes: Without treatment OCD persists throughout life with functional impairment.
  evidence:
  - reference: PMID:37859440
    reference_title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      OCD typically starts in childhood or adolescence and persists throughout
      life
    explanation: >-
      OCD follows a persistent, chronic course.
environmental:
- name: Streptococcal infection (PANDAS)
  description: >-
    In a subset of children, group A streptococcal infection is associated with
    the abrupt onset of obsessive-compulsive symptoms and/or tics (pediatric
    autoimmune neuropsychiatric disorders associated with streptococcal
    infections, PANDAS), proposed to reflect an autoimmune/neuroinflammatory
    mechanism. The diagnosis remains controversial.
  evidence:
  - reference: PMID:34778136
    reference_title: "Diagnostic Approach to Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS): A Narrative Review of Literature Data"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      are clinical conditions characterized by the sudden onset of
      obsessive-compulsive disorder and/or tics
    explanation: >-
      PANDAS links streptococcal infection to acute-onset OCD in a subset of
      children, an environmental/immune trigger.
diagnosis:
- name: Clinical DSM-5 diagnosis
  presence: >-
    Diagnosis is clinical, based on the presence of time-consuming obsessions
    and/or compulsions that cause marked distress or functional impairment, with
    a specifier for level of insight.
  diagnosis_term:
    preferred_term: clinical assessment
    term:
      id: MAXO:0000487
      label: clinical assessment
  evidence:
  - reference: PMID:37137502
    reference_title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      current diagnostic criteria, and common comorbidities
    explanation: >-
      Review describes standardized OCD diagnostic criteria.
- name: Yale-Brown Obsessive-Compulsive Scale (Y-BOCS)
  presence: >-
    The Y-BOCS is the standard instrument for grading OCD symptom severity and
    monitoring treatment response.
  evidence:
  - reference: PMID:40629326
    reference_title: "Obsessive-compulsive disorder in the World Mental Health surveys"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Most OCD cases in the community are mild (47.0%) or very mild (27.5%),
      with a smaller percentage designated as moderate (22.9%) or severe (2.7%)
      by the Yale-Brown Obsessive-Compulsive Scale.
    explanation: >-
      Y-BOCS is used to grade OCD severity in epidemiological samples.
differential_diagnoses:
- name: Body dysmorphic disorder
  description: >-
    An obsessive-compulsive and related disorder featuring preoccupation with
    perceived physical defects and related repetitive behaviors.
  disease_term:
    preferred_term: body dysmorphic disorder
    term:
      id: MONDO:0000690
      label: body dysmorphic disorder
  distinguishing_features:
  - Preoccupations focus specifically on perceived appearance defects rather than broader obsessional themes.
  evidence:
  - reference: PMID:37859440
    reference_title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      removed OCD from the anxiety disorder grouping and regrouped it into
      obsessive-compulsive and related disorders
    explanation: >-
      Body dysmorphic disorder is part of the obsessive-compulsive and related
      disorders spectrum distinguished from OCD.
- name: Trichotillomania
  description: >-
    A body-focused repetitive behavior disorder (hair-pulling) within the
    obsessive-compulsive and related disorders spectrum.
  disease_term:
    preferred_term: trichotillomania
    term:
      id: MONDO:0013189
      label: trichotillomania
  distinguishing_features:
  - Repetitive hair-pulling is not driven by obsessions and is typically not anxiety-reducing in the OCD sense.
  evidence:
  - reference: PMID:37859440
    reference_title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      removed OCD from the anxiety disorder grouping and regrouped it into
      obsessive-compulsive and related disorders
    explanation: >-
      Trichotillomania is part of the obsessive-compulsive and related disorders
      spectrum distinguished from OCD.
- name: Tourette syndrome
  description: >-
    A tic disorder that frequently co-occurs with OCD and shares genetic risk,
    but is defined by motor and vocal tics rather than obsessions/compulsions.
  disease_term:
    preferred_term: Tourette syndrome
    term:
      id: MONDO:0007661
      label: Tourette syndrome
  distinguishing_features:
  - Defined by involuntary motor/vocal tics rather than obsession-driven compulsions.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD shared genetic risk with anxiety, depression, anorexia nervosa and
      Tourette syndrome
    explanation: >-
      OCD shares genetic risk with Tourette syndrome, a key differential and
      comorbidity.
- name: Generalized anxiety disorder
  description: >-
    A differential characterized by pervasive, excessive worry about everyday
    matters rather than discrete intrusive obsessions and ritualized
    compulsions.
  disease_term:
    preferred_term: generalized anxiety disorder
    term:
      id: MONDO:0001942
      label: generalized anxiety disorder
  distinguishing_features:
  - Worries are about realistic life concerns and are not neutralized by compulsive rituals.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      OCD shared genetic risk with anxiety, depression, anorexia nervosa and
      Tourette syndrome
    explanation: >-
      OCD shares genetic liability with anxiety disorders, a frequent
      differential; the snippet supports the shared-risk relationship.
- name: Obsessive-compulsive personality disorder
  description: >-
    A personality disorder of perfectionism, orderliness, and control that is
    ego-syntonic, distinct from the ego-dystonic obsessions and compulsions of
    OCD.
  disease_term:
    preferred_term: obsessive-compulsive personality disorder
    term:
      id: MONDO:0001158
      label: obsessive-compulsive personality disorder
  distinguishing_features:
  - Traits are ego-syntonic (experienced as appropriate) rather than ego-dystonic intrusive obsessions.
animal_models:
- species: Mouse
  genotype: Sapap3 knockout (Sapap3-/-, Dlgap3-/-)
  description: >-
    Genetic deletion of Sapap3 (DLGAP3), a postsynaptic scaffolding protein at
    cortico-striatal excitatory synapses, produces increased anxiety and
    compulsive grooming with self-inflicted skin lesions and cortico-striatal
    synaptic defects, reversible by an SSRI. A leading OCD mouse model.
  evidence:
  - reference: PMID:17713528
    reference_title: "Cortico-striatal synaptic defects and OCD-like behaviours in Sapap3-mutant mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      mice with genetic deletion of Sapap3 exhibit increased anxiety and
      compulsive grooming behaviour leading to facial hair loss and skin
      lesions; both behaviours are alleviated by a selective serotonin reuptake
      inhibitor
    explanation: >-
      Sapap3-knockout mice recapitulate compulsive grooming and anxiety
      responsive to SSRIs.
- species: Mouse
  genotype: Slitrk5 knockout (Slitrk5-/-)
  description: >-
    Loss of the synaptic transmembrane protein Slitrk5 causes excessive
    self-grooming, increased anxiety, orbitofrontal overactivation, and striatal
    abnormalities, alleviated by fluoxetine.
  evidence:
  - reference: PMID:20418887
    reference_title: "Slitrk5 deficiency impairs corticostriatal circuitry and leads to obsessive-compulsive-like behaviors in mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      loss of a neuron-specific transmembrane protein, SLIT and NTRK-like
      protein-5 (Slitrk5), leads to OCD-like behaviors in mice, which manifests
      as excessive self-grooming and increased anxiety-like behaviors, and is
      alleviated by the selective serotonin reuptake inhibitor fluoxetine
    explanation: >-
      Slitrk5-knockout mice model compulsive grooming and anxiety responsive to
      an SSRI.
- species: Mouse
  genotype: Slc1a1/EAAT3 loss (Slc1a1-STOP)
  description: >-
    Ablation of the OCD candidate glutamate transporter EAAT3 (Slc1a1) alters
    basal ganglia-dependent repetitive behaviors and dopaminergic function,
    linking the most consistently associated OCD candidate gene to striatal
    circuitry.
  evidence:
  - reference: PMID:28507136
    reference_title: "OCD candidate gene SLC1A1/EAAT3 impacts basal ganglia-mediated activity and stereotypic behavior"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      these findings indicate that the most consistently associated OCD
      candidate gene impacts basal ganglia-dependent repetitive behaviors
    explanation: >-
      Slc1a1/EAAT3 loss in mice alters basal ganglia-dependent repetitive
      behavior.
- species: Mouse
  genotype: Hoxb8 knockout (Hoxb8-/-)
  description: >-
    Hoxb8 mutant mice exhibit fully penetrant excessive grooming causing hair
    removal and skin lesions, a pathological grooming phenotype likened to the
    OC-spectrum disorder trichotillomania and traced to CNS (microglial)
    abnormalities.
  evidence:
  - reference: PMID:11779477
    reference_title: "Hoxb8 is required for normal grooming behavior in mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      mice with disruptions of Hoxb8 show, with 100% penetrance, excessive
      grooming leading to hair removal and lesions.
    explanation: >-
      Hoxb8-knockout mice model pathological grooming relevant to OC-spectrum
      behavior.
- species: Mouse
  genotype: Optogenetic OFC-VMS hyperstimulation (wild-type)
  category: Induced
  description: >-
    Repeated optogenetic hyperactivation of orbitofrontal cortex (OFC) to
    ventromedial striatum (VMS) projections generates a progressive, persistent
    increase in grooming, causally implicating CSTC corticostriatal
    hyperactivity in OCD-like repetitive behavior.
  evidence:
  - reference: PMID:23744948
    reference_title: "Repeated cortico-striatal stimulation generates persistent OCD-like behavior"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      repeated hyperactivation over multiple days generated a progressive
      increase in grooming, a mouse behavior related to OCD
    explanation: >-
      Optogenetic OFC-VMS hyperstimulation causally produces persistent
      OCD-like grooming, supporting the CSTC circuit model.
mechanistic_hypotheses:
- hypothesis_group_id: canonical_cstc_serotonergic_glutamatergic
  hypothesis_label: Canonical CSTC Circuit / Serotonergic-Glutamatergic Model
  status: CANONICAL
  description: >-
    OCD arises from hyperactivity and imbalance within cortico-striato-thalamo-
    cortical (CSTC) loops (orbitofrontal cortex, anterior cingulate cortex,
    caudate, thalamus), shaped by serotonergic, glutamatergic, and dopaminergic
    neurotransmission. The selective efficacy of serotonin reuptake inhibitors,
    consistent functional-imaging evidence of CSTC hyperactivity, and benefit of
    CSTC-targeted neuromodulation (TMS, deep brain stimulation) converge on this
    model.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Functional imaging studies in OCD show consistent evidence for increased
      activity in brain regions that form a cortico-striato-thalamo-cortical
      (CSTC) loop.
    explanation: >-
      Imaging evidence for CSTC hyperactivity anchors the canonical model.
- hypothesis_group_id: emerging_neuroimmune_mhc
  hypothesis_label: Emerging Neuroimmune / MHC Contribution
  status: EMERGING
  description: >-
    Genome-wide association implicates the major histocompatibility complex
    (MHC) region in OCD risk, and PANDAS links streptococcal infection to
    acute-onset OCD, suggesting a neuroimmune/neuroinflammatory contribution
    that remains to be mechanistically resolved.
  evidence:
  - reference: PMID:40360802
    reference_title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      multiple genes in the major histocompatibility complex (MHC) region
    explanation: >-
      GWAS implication of the MHC region motivates a neuroimmune hypothesis,
      though the causal mechanism is unresolved.
clinical_trials:
- name: NCT03299166
  phase: PHASE_III
  status: COMPLETED
  description: >-
    Randomized, double-blind, placebo-controlled Phase 2/3 trial of adjunctive
    troriluzole (a glutamate-modulating prodrug of riluzole) in adults with OCD
    and inadequate response to serotonergic pharmacotherapy, testing the
    glutamatergic-dysregulation hypothesis therapeutically.
  target_phenotypes:
  - preferred_term: Obsessions and compulsions
    term:
      id: HP:0008770
      label: Obsessive-compulsive trait
  evidence:
  - reference: clinicaltrials:NCT03299166
    reference_title: "A Randomized, Double-blind, Placebo-controlled Trial of Adjunctive Troriluzole in Obsessive Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The purpose of this study is to evaluate the efficacy of troriluzole as
      adjunctive therapy versus placebo in participants with obsessive
      compulsive disorder (OCD) who had an inadequate response to selective
      serotonin reuptake inhibitor (SSRI), clomipramine, venlafaxine, or
      desvenlafaxine treatment
    explanation: >-
      Trial of an adjunctive glutamate modulator directly tests the
      glutamatergic-imbalance mechanism in treatment-resistant OCD.
- name: NCT02229903
  phase: NOT_APPLICABLE
  status: COMPLETED
  description: >-
    Randomized, double-blind, multicenter, sham-controlled trial of deep
    transcranial magnetic stimulation (dTMS) over medial prefrontal/anterior
    cingulate cortex in OCD; the pivotal study supporting FDA clearance of dTMS
    for OCD and a clinical test of the CSTC neuromodulation model.
  target_phenotypes:
  - preferred_term: Obsessions and compulsions
    term:
      id: HP:0008770
      label: Obsessive-compulsive trait
  evidence:
  - reference: clinicaltrials:NCT02229903
    reference_title: "A Prospective Double Blind Randomized Controlled Trial to Evaluate the Safety and Efficacy of the Deep Transcranial Magnetic Stimulation (dTMS) in Obsessive-Compulsive Subjects"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The Brainsway DTMS study is a randomized, 10 week, double blind,
      multi-center trial comparing active DTMS treatment to sham treatment.
    explanation: >-
      Sham-controlled multicenter dTMS trial tests CSTC-targeted neuromodulation
      as a treatment for OCD.
- name: NCT03356483
  phase: PHASE_I
  status: COMPLETED
  description: >-
    Double-blind, placebo-controlled study of oral psilocybin in OCD, probing
    serotonergic (5-HT2A) psychedelic modulation of OCD symptoms and its neural
    correlates.
  target_phenotypes:
  - preferred_term: Obsessions and compulsions
    term:
      id: HP:0008770
      label: Obsessive-compulsive trait
  evidence:
  - reference: clinicaltrials:NCT03356483
    reference_title: "Psilocybin Treatment in Obsessive-Compulsive Disorder: a Preliminary Efficacy Study and Exploratory Investigation of Neural Correlates."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      This study aims to investigate the effects of oral psilocybin on OCD
      symptomatology and provide the first evidence of the neural mechanism that
      may mediate psilocybin's purported therapeutic effects on OCD.
    explanation: >-
      Psilocybin trial tests serotonergic 5-HT2A modulation as a novel
      mechanism-based treatment for OCD.
discussions:
- discussion_id: gap_ocd_serotonergic_paradox
  prompt: >-
    Why are serotonin reuptake inhibitors preferentially effective in OCD when
    no consistent primary serotonergic abnormality has been identified, and what
    is the true molecular target of their anti-obsessional effect?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Serotonergic Neurotransmission Dysregulation
  - treatment#Selective Serotonin Reuptake Inhibitors
  rationale: >-
    The serotonergic hypothesis of OCD rests almost entirely on the selective
    therapeutic response to SRIs (a "pharmacological dissection"), yet decades of
    work have not localized a primary serotonergic lesion. This leaves the
    mechanism by which SRIs reduce obsessions and compulsions — and whether it is
    serotonergic at all rather than downstream CSTC-circuit remodeling —
    unresolved.
  evidence:
  - reference: PMID:33384007
    reference_title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The preferential efficacy of SRIs in OCD has neither led to discovery of
      serotonergic abnormalities in OCD nor to development of new serotonergic
      medications for OCD.
    explanation: >-
      A leading review states explicitly that SRI efficacy has not been
      reconciled with any identified serotonergic abnormality, defining the gap.
- discussion_id: mismatch_ocd_animal_models_obsessions
  prompt: >-
    Do rodent compulsive-grooming knockout models (Sapap3, Slitrk5, Slc1a1)
    faithfully model human OCD, given that they reproduce repetitive
    compulsive-like motor behavior but cannot capture the intrusive obsessions,
    symptom dimensions, and fluctuating insight that define the human disorder?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - genetic#SLITRK5
  - genetic#DLGAP3
  - genetic#SLC1A1
  - pathophysiology#Cortico-Striato-Thalamo-Cortical Circuit Dysfunction
  rationale: >-
    The strongest mechanistic evidence for cortico-striatal causation in OCD
    comes from mouse knockouts that develop excessive grooming reversible by
    SSRIs. However, grooming is a motor stereotypy; obsessions are
    cognitive-affective phenomena with no clear rodent analog, and insight is
    uniquely human. Whether these models inform the obsessional/cognitive core
    of OCD — or only its compulsive motor output — is mechanistically
    consequential for target validation.
  proposed_experiments:
  - experiment_id: exp_ocd_cross_species_cstc_alignment
    name: Cross-species CSTC circuit readout alignment
    description: >-
      Map orbitofrontal-striatal activity signatures associated with
      compulsive grooming in Sapap3/Slitrk5 mice onto task-based fMRI CSTC
      signatures in human OCD to test whether the same circuit state underlies
      rodent compulsions and human symptoms, distinguishing shared compulsive
      circuitry from human-specific obsessional processing.
  evidence:
  - reference: PMID:20418887
    reference_title: "Slitrk5 deficiency impairs corticostriatal circuitry and leads to obsessive-compulsive-like behaviors in mice"
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: >-
      provide a new mouse model of OCD-like behaviors
    explanation: >-
      The model is explicitly described as reproducing OCD-"like" behaviors,
      underscoring that it captures a behavioral analog rather than the full
      human syndrome.
references:
- reference: PMID:33384007
  title: "Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder"
- reference: PMID:37137502
  title: "Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction"
- reference: PMID:40360802
  title: "Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder"
- reference: PMID:37859440
  title: "Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults"
- reference: PMID:40629326
  title: "Obsessive-compulsive disorder in the World Mental Health surveys"
- reference: PMID:17713528
  title: "Cortico-striatal synaptic defects and OCD-like behaviours in Sapap3-mutant mice"
- reference: PMID:34778136
  title: "Diagnostic Approach to Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS): A Narrative Review of Literature Data"
- reference: PMID:33146050
  title: "Multifaceted impulsivity in obsessive-compulsive disorder with hoarding symptoms"
- reference: PMID:11779477
  title: "Hoxb8 is required for normal grooming behavior in mice"
- reference: PMID:23744948
  title: "Repeated cortico-striatal stimulation generates persistent OCD-like behavior"
📚

References & Deep Research

References

10
Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder
No top-level findings curated for this source.
Obsessive-compulsive disorder: Etiology, neuropathology, and cognitive dysfunction
No top-level findings curated for this source.
Genome-wide analyses identify 30 loci associated with obsessive-compulsive disorder
No top-level findings curated for this source.
Clinical Advances in Treatment Strategies for Obsessive-compulsive Disorder in Adults
No top-level findings curated for this source.
Obsessive-compulsive disorder in the World Mental Health surveys
No top-level findings curated for this source.
Cortico-striatal synaptic defects and OCD-like behaviours in Sapap3-mutant mice
No top-level findings curated for this source.
Diagnostic Approach to Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS): A Narrative Review of Literature Data
No top-level findings curated for this source.
Multifaceted impulsivity in obsessive-compulsive disorder with hoarding symptoms
No top-level findings curated for this source.
Hoxb8 is required for normal grooming behavior in mice
No top-level findings curated for this source.
Repeated cortico-striatal stimulation generates persistent OCD-like behavior
No top-level findings curated for this source.

Deep Research

1
Falcon
1. Disease Information
Edison Scientific Literature 16 citations 2026-06-21T11:04:09.877913

1. Disease Information

Overview and Definition

Obsessive-Compulsive Disorder (OCD) is a neuropsychiatric condition characterized by unwanted obsessions (repetitive thoughts, images, or urges) and/or compulsions (repetitive behaviors or mental acts) that cause significant distress and functional impairment (jalal2023obsessive‐compulsivedisorderetiology pages 1-2, roh2023clinicaladvancesin pages 1-2). OCD affects approximately 1-3% of the general population, making it a common psychiatric disorder with substantial public health burden (jalal2023obsessive‐compulsivedisorderetiology pages 1-2, stein2025obsessivecompulsivedisorderin pages 1-2, strom2025genomewideanalysesidentify pages 1-2).

Classification and Identifiers

In the DSM-5 and ICD-11, OCD was reclassified from the anxiety disorder category to a new grouping called "Obsessive-Compulsive and Related Disorders" (OCRD), reflecting improved understanding of its distinct neurobiological substrates (jalal2023obsessive‐compulsivedisorderetiology pages 1-2, roh2023clinicaladvancesin pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3). This category includes hoarding disorder, body dysmorphic disorder, trichotillomania, and excoriation disorder (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Diagnostic Criteria

According to DSM-5, diagnosis requires the presence of obsessions and/or compulsions that are time-consuming (taking more than one hour per day) and cause significant distress or interfere with everyday activities including social and occupational functioning (jalal2023obsessive‐compulsivedisorderetiology pages 1-2). The DSM-5 includes a specifier for insight level, recognizing that patients vary from good/fair insight to absent insight or delusional beliefs (jalal2023obsessive‐compulsivedisorderetiology pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

2. Etiology

Disease Causal Factors

OCD etiology involves a complex interplay of genetic vulnerability, environmental exposures, and neurobiological mechanisms (dhiman2025hereditarypatternsand pages 1-1, roh2023clinicaladvancesin pages 1-2, liu2023earlyidentificationand pages 1-2).

Risk Factors

Genetic Risk Factors: OCD demonstrates substantial heritability. Twin-based heritability estimates range from 27-47% in adults and 45-65% in children, with pediatric-onset OCD showing higher genetic loading than adult-onset cases (dhiman2025hereditarypatternsand pages 1-1, strom2025genomewideanalysesidentify pages 1-2, liu2023earlyidentificationand pages 1-2). Family studies indicate genetic contribution of 35-50% (roh2023clinicaladvancesin pages 1-2).

The largest genome-wide association study (GWAS) meta-analysis to date, combining 53,660 OCD cases and 2,044,417 controls, identified 30 independent genome-wide significant loci (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 2-3). Key findings include: - Approximately 11,500 genetic variants explain 90% of OCD genetic heritability, indicating highly polygenic architecture (strom2025genomewideanalysesidentify pages 2-3) - SNP-based heritability estimated at 6.7% (SE 0.3%) assuming 1% population prevalence, with higher estimates in clinically ascertained samples (strom2025genomewideanalysesidentify pages 2-3) - Priority candidate genes include WDR6, DALRD3, and CTNND1, along with multiple genes in the major histocompatibility complex (MHC) region (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4)

Environmental Risk Factors: While specific environmental factors remain under investigation, adverse lifetime experiences may induce neurobiological adaptations within a genetic vulnerability window (roh2023clinicaladvancesin pages 1-2). The OCDTWIN project is systematically investigating environmental risk factors through discordant monozygotic twin pairs (dhiman2025hereditarypatternsand pages 1-1).

Gene-Environment Interactions: Limited direct evidence exists for specific gene-environment interactions in OCD, though the OCDTWIN study aims to isolate unique environmental risk factors in the causal pathway while controlling for genetic influences (dhiman2025hereditarypatternsand pages 1-1).

Gene/Locus Chromosome Location Function/Description Evidence Type (GWAS/TWAS/PWAS) P-value or significance Key Findings
OCD GWAS meta-analysis summary Genome-wide Large-scale common-variant architecture of OCD GWAS 30 independent genome-wide significant loci in 53,660 cases and 2,044,417 controls; 1,672 SNPs exceeded genome-wide significance; threshold P < 5×10⁻⁸ (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 2-3) Largest reported OCD GWAS identified 30 loci, substantially expanding prior findings and supporting a highly polygenic architecture (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 2-3)
Polygenic architecture Genome-wide Aggregate common-variant contribution to OCD risk GWAS / MiXeR ~11,500 causal variants (SE 607) explain 90% of OCD SNP-based heritability (strom2025genomewideanalysesidentify pages 2-3) Indicates OCD risk is distributed across thousands of variants rather than a few high-penetrance loci, consistent with complex polygenic inheritance (strom2025genomewideanalysesidentify pages 2-3)
SNP-based heritability Genome-wide Common-variant heritability estimate GWAS h²SNP 6.7% (SE 0.3%) overall assuming 1% prevalence; subgroup estimates higher in clinically ascertained samples; earlier published estimates ranged ~8.5% to 16%, with older reports up to 28–37% depending on design/assumptions (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 2-3) Supports measurable but incomplete capture of total OCD heritability by common SNPs; twin-based heritability remains higher than SNP-based estimates (strom2025genomewideanalysesidentify pages 1-2)
Twin/family heritability Genome-wide Familial genetic contribution Family/twin studies summarized in review Adults ~27–47%; children ~45–65% (strom2025genomewideanalysesidentify pages 1-2); broader review notes genetic contribution ~35–50% (roh2023clinicaladvancesin pages 1-2) Higher heritability in pediatric-onset OCD supports stronger genetic loading in early-onset presentations (strom2025genomewideanalysesidentify pages 1-2, liu2023earlyidentificationand pages 1-2)
WDR6 2q33 WD repeat domain 6; prioritized likely causal effector gene GWAS + gene prioritization + TWAS-COLOC/SMR-HEIDI Among 25 genes prioritized as most likely causal; implicated by multiple methods (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4) One of only two genes prioritized by both TWAS-COLOC and SMR-HEIDI filters, strengthening causal inference beyond positional association alone (strom2025genomewideanalysesidentify pages 3-4)
DALRD3 2q33 DALR anticodon binding domain-containing 3; prioritized likely causal effector gene GWAS + gene prioritization + TWAS-COLOC/SMR-HEIDI Among 25 genes prioritized as most likely causal; implicated by multiple methods (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4) Along with WDR6, one of the strongest cross-method priority genes, supported by convergent colocalization/causality filters (strom2025genomewideanalysesidentify pages 3-4)
CTNND1 6p22 Catenin delta-1; adhesion/synaptic-related gene, prioritized candidate GWAS + TWAS + PWAS + colocalization CTNND1 protein downregulation in human dlPFC associated with OCD risk: Z = -4.49, P = 7.11×10⁻⁶; TWAS in prefrontal cortex: Z = -6.86, P = 6.90×10⁻¹² (strom2025genomewideanalysesidentify pages 3-4) Especially notable because it was implicated by three orthogonal approaches (mBAT-combo, TWAS, PWAS) and also showed evidence for colocalization, making it one of the most biologically convergent OCD genes (strom2025genomewideanalysesidentify pages 3-4)
MHC region / 6p21.33 locus 6p21.33 Major histocompatibility complex region; dense immune-related locus GWAS Lead SNP rs4990036, P = 1.45×10⁻¹¹; 118 genes within regional window (strom2025genomewideanalysesidentify pages 2-3) MHC-region signal suggests possible neuroimmune contribution to OCD biology, although fine-mapping is challenging because of high linkage disequilibrium and gene density (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 2-3)
rs78587207 locus 11q12.1 Genome-wide significant lead SNP region GWAS P = 5.28×10⁻¹² (strom2025genomewideanalysesidentify pages 2-3) One of the strongest individual loci in the meta-analysis; also overlaps signals seen in schizophrenia, well-being, neuroticism, and educational attainment databases (strom2025genomewideanalysesidentify pages 2-3)
rs13262595 locus 8q24.3 Genome-wide significant lead SNP region GWAS P = 1.31×10⁻¹¹ (strom2025genomewideanalysesidentify pages 2-3) Strong association signal with cross-trait overlap including schizophrenia, neuroticism, and educational attainment, highlighting pleiotropy (strom2025genomewideanalysesidentify pages 2-3)
rs10877425 locus 12q14.1 Genome-wide significant lead SNP region GWAS P = 1.62×10⁻¹¹ (strom2025genomewideanalysesidentify pages 2-3) High-confidence OCD locus without a highlighted nearby gene in the summary table, illustrating that some strong associations remain functionally unresolved (strom2025genomewideanalysesidentify pages 2-3)
rs7626445 locus 3p21.31 Genome-wide significant lead SNP region GWAS P = 1.74×10⁻¹¹ (strom2025genomewideanalysesidentify pages 2-3) Associated region overlaps neuroticism, smoking, blood cell count, and height traits, again indicating polygenic pleiotropy (strom2025genomewideanalysesidentify pages 2-3)
rs2564930 locus 3p21.1 Genome-wide significant lead SNP region GWAS P = 3.41×10⁻¹¹ (strom2025genomewideanalysesidentify pages 2-3) Strong signal in a region also linked to schizophrenia, neuroticism, blood cell count, and BMI (strom2025genomewideanalysesidentify pages 2-3)
rs4702 locus 15q26.1 Genome-wide significant lead SNP region GWAS P = 9.07×10⁻¹⁰ (strom2025genomewideanalysesidentify pages 2-3) Notable because the same locus shows associations with bipolar disorder, major depressive disorder, and risk-taking behavior, consistent with shared psychiatric liability (strom2025genomewideanalysesidentify pages 2-3)
Gene-based discovery summary Genome-wide Aggregated gene-level prioritization from multiple methods mBAT-combo / TWAS / SMR / PWAS / PsyOPS 251 genes significant in at least one gene-based method; 48 genes implicated by ≥2 methods; 25 genes passed additional causal-support filters (strom2025genomewideanalysesidentify pages 2-3, strom2025genomewideanalysesidentify pages 3-4) Multi-method integration greatly narrowed the candidate list from hundreds of genes to a smaller set of more plausible effector genes for functional follow-up (strom2025genomewideanalysesidentify pages 2-3, strom2025genomewideanalysesidentify pages 3-4)
Tissue enrichment Brain tissues Regional expression enrichment of OCD-associated genes MAGMA / LDSC Enrichment seen in anterior cingulate cortex, frontal cortex, cortex, nucleus accumbens, hippocampus, caudate, putamen, hypothalamus, substantia nigra, cerebellum and related brain tissues (strom2025genomewideanalysesidentify pages 3-4) Supports a brain-circuit model centered on cortico-striatal and limbic systems rather than a diffuse whole-body signal (strom2025genomewideanalysesidentify pages 3-4, jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Cell-type enrichment Hippocampus, cortex, striatum Neuronal cell classes implicated by genetic risk Single-cell enrichment from GWAS signals Significant enrichment in excitatory neurons in hippocampus/cortex and D1/D2 dopamine receptor-containing medium spiny neurons in striatum (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4) Provides cell-type specificity linking OCD genetic risk to excitatory cortical/hippocampal neurons and striatal medium spiny neurons, consistent with CSTC circuit models (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4, jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Cross-trait genetic correlations Genome-wide Shared inherited liability with other disorders/traits GWAS genetic correlation OCD shared genetic risk with 65 of 112 phenotypes; especially anxiety, depression, anorexia nervosa, Tourette syndrome; negative associations with inflammatory bowel diseases, educational attainment, and BMI (strom2025genomewideanalysesidentify pages 1-2) Reinforces that OCD genetics overlap substantially with other psychiatric phenotypes while also showing inverse relationships with some immune/metabolic traits (strom2025genomewideanalysesidentify pages 1-2)
Ascertainment and heterogeneity analyses Genome-wide Robustness of results across cohorts GWAS / GenomicSEM No statistically significant heterogeneity across the 30 lead loci by Cochran’s Q; moderate-to-high genetic correlations across ascertainment subgroups (strom2025genomewideanalysesidentify pages 2-3) Suggests that major loci are broadly consistent across different OCD cohorts, even though ascertainment strategy influences genome-wide architecture to some extent (strom2025genomewideanalysesidentify pages 2-3)

Table: This table summarizes the major genetic findings for obsessive-compulsive disorder from recent large-scale GWAS and gene-prioritization analyses. It highlights the most important loci, candidate genes, heritability estimates, and polygenic architecture features that are most useful for a disease knowledge base.

3. Phenotypes

Symptom Dimensions

OCD symptoms are classified into partially distinct subtypes (jalal2023obsessive‐compulsivedisorderetiology pages 2-3): 1. Contamination fears and compulsive cleaning 2. Obsessive thoughts about causing harm and compulsive checking 3. Obsessions with symmetry and compulsive ordering 4. Obsessions with collecting and compulsive hoarding (now a separate disorder in DSM-5) 5. Purely obsessional subtype with unwanted thoughts about sex, violence, and blasphemy

Suggested HPO Terms: - HP:0000722 (Obsessive-compulsive behavior) - HP:0000733 (Repetitive compulsive behavior) - HP:0000723 (Restricted interests)

Phenotype Characteristics

Age of Onset: OCD demonstrates a bimodal onset with peaks at 12-14 years and 20-22 years (liu2023earlyidentificationand pages 1-2). More than 80% of OCD cases begin by early adulthood (stein2025obsessivecompulsivedisorderin pages 1-2). Half of adult patients exhibited symptoms starting in childhood or adolescence (farrell2023closingthegap pages 1-2, liu2023earlyidentificationand pages 1-2).

Severity: In community samples, most OCD cases are mild (47.0%) or very mild (27.5%), with smaller percentages designated as moderate (22.9%) or severe (2.7%) by Yale-Brown Obsessive-Compulsive Scale (stein2025obsessivecompulsivedisorderin pages 1-2).

Progression: OCD typically starts in childhood or adolescence and often persists throughout life, causing functional impairment across multiple domains (roh2023clinicaladvancesin pages 1-2). The 12-month prevalence (3.0%) is nearly as high as lifetime prevalence (4.1%), suggesting highly persistent course (stein2025obsessivecompulsivedisorderin pages 1-2).

Quality of Life Impact

OCD causes substantial disability and is among the leading causes of illness-related burden according to the World Health Organization (roh2023clinicaladvancesin pages 1-2, farrell2023closingthegap pages 1-2). Childhood onset is associated with greater OCD severity, more symptoms, higher comorbidity, and poorer prognosis relative to adult onset (farrell2023closingthegap pages 1-2).

4. Genetic/Molecular Information

Causal Genes and Pathogenic Variants

The 2025 GWAS meta-analysis identified 249 potential effector genes for OCD, with 25 classified as most likely causal candidates (strom2025genomewideanalysesidentify pages 1-2). Key genes include:

  • WDR6 (2q33): WD repeat domain 6, prioritized by both TWAS-COLOC and SMR-HEIDI causality filters (strom2025genomewideanalysesidentify pages 3-4)
  • DALRD3 (2q33): DALR anticodon binding domain-containing 3, also prioritized by convergent causal inference methods (strom2025genomewideanalysesidentify pages 3-4)
  • CTNND1 (6p22): Catenin delta-1, implicated by three orthogonal approaches (mBAT-combo, TWAS, PWAS) with evidence for colocalization; protein downregulation in dorsolateral prefrontal cortex associated with OCD risk (Z = -4.49, P = 7.11×10⁻⁶) (strom2025genomewideanalysesidentify pages 3-4)
  • MHC region genes (6p21.33): Multiple genes in the major histocompatibility complex region (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 2-3)

Variant Classification

The current evidence primarily derives from common variant GWAS rather than rare coding variants. The polygenic architecture suggests thousands of small-effect variants rather than high-penetrance mutations (strom2025genomewideanalysesidentify pages 2-3).

Cell Type and Tissue Enrichment

OCD genetic risk shows significant enrichment in: - Excitatory neurons in hippocampus and cerebral cortex - D1 and D2 type dopamine receptor-containing medium spiny neurons in the striatum (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4)

Tissue enrichment analysis revealed significant signals in anterior cingulate cortex, frontal cortex, nucleus accumbens, hippocampus, caudate, putamen, hypothalamus, and cerebellum (strom2025genomewideanalysesidentify pages 3-4).

5. Environmental Information

Environmental Factors

The specific environmental contributors to OCD remain under active investigation. The OCDTWIN project is systematically evaluating early life exposures including perinatal variables, psychosocial stressors, and health-related information through register linkages (dhiman2025hereditarypatternsand pages 1-1).

Lifestyle Factors

Limited specific data available from retrieved sources.

6. Mechanism / Pathophysiology

Molecular Pathways

The dominant pathophysiological model implicates dysfunction in cortico-striato-thalamo-cortical (CSTC) circuits (jalal2023obsessive‐compulsivedisorderetiology pages 1-2, roh2023clinicaladvancesin pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3). These parallel circuits are responsible for reward and motivational processes, executive function, motor and response inhibition, and habit-based behavior (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Key CSTC circuits include (jalal2023obsessive‐compulsivedisorderetiology pages 2-3): 1. Affective circuit: Projects from anterior cingulate cortex (ACC) and ventromedial prefrontal cortex (vmPFC) to nucleus accumbens, involved in emotion and reward processing 2. Dorsal cognitive circuit: Projects from dorsolateral prefrontal cortex (dlPFC) to caudate nucleus, pertinent to executive function and working memory 3. Ventral cognitive circuit: Projects from anterolateral orbitofrontal cortex to putamen, responsible for motor and response inhibition 4. Sensorimotor circuit: Projects from premotor cortical regions to putamen, involved in habit-based behavior

Neurochemical Systems

Serotonin: Dysfunction in serotonergic neurotransmission is strongly implicated, as evidenced by the efficacy of selective serotonin reuptake inhibitors (SSRIs) (roh2023clinicaladvancesin pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Dopamine: Dopaminergic systems play an important role, particularly in striatal function and the generation of compulsive behaviors (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Glutamate: Glutamatergic dysregulation within CSTC circuits is increasingly recognized as contributing to OCD pathophysiology (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Cellular Processes

OCD involves aberrant activity within CSTC circuits, with evidence of overactivity in orbitofrontal cortex and striatum that can normalize following successful pharmacological and psychological treatment (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Suggested GO Terms: - GO:0007165 (Signal transduction) - GO:0007268 (Chemical synaptic transmission) - GO:0042493 (Response to drug) - GO:0050890 (Cognition)

Suggested CL Terms: - CL:0000540 (Neuron) - CL:0000100 (Motor neuron) - CL:0000679 (Glutamatergic neuron)

7. Anatomical Structures Affected

Organ and System Level

Primary Organs: Central nervous system, particularly brain regions within CSTC circuits

Brain Systems: - Orbitofrontal cortex (OFC) - Anterior cingulate cortex (ACC) - Dorsolateral prefrontal cortex (dlPFC) - Ventromedial prefrontal cortex (vmPFC) - Striatum (caudate nucleus, putamen, nucleus accumbens) - Thalamus - Cerebellum (jalal2023obsessive‐compulsivedisorderetiology pages 2-3, strom2025genomewideanalysesidentify pages 3-4)

Cell and Tissue Level

Cell Types Affected: - Excitatory neurons in hippocampus and cortex - D1 and D2 dopamine receptor-containing medium spiny neurons in striatum (strom2025genomewideanalysesidentify pages 1-2, strom2025genomewideanalysesidentify pages 3-4)

Suggested UBERON Terms: - UBERON:0000955 (Brain) - UBERON:0002037 (Cerebellum) - UBERON:0001950 (Neocortex) - UBERON:0002435 (Striatum) - UBERON:0001897 (Thalamus)

8. Temporal Development

Onset

Typical Age of Onset: Bimodal distribution with peaks at 12-14 years and 20-22 years (liu2023earlyidentificationand pages 1-2). More than 80% of cases begin by early adulthood, with more than half of adult OCD patients having onset in childhood or adolescence (stein2025obsessivecompulsivedisorderin pages 1-2, farrell2023closingthegap pages 1-2).

Onset Pattern: Can be acute, subacute, or insidious. Childhood-onset OCD is associated with greater severity and higher genetic loading compared to adult-onset (farrell2023closingthegap pages 1-2, liu2023earlyidentificationand pages 1-2).

Progression

Disease Course: OCD typically demonstrates a chronic course with high persistence. The 12-month prevalence (3.0%) nearly equals lifetime prevalence (4.1%), suggesting minimal spontaneous remission (stein2025obsessivecompulsivedisorderin pages 1-2). Studies in youth suggest a higher percentage have an episodic course compared to adults (liu2023earlyidentificationand pages 1-2).

Duration: Delayed diagnosis is common, with a gap between onset and diagnosis of approximately 7-10 years in adults and more than 2 years in children (liu2023earlyidentificationand pages 1-2). Australian data suggest more than 9 years of untreated illness for OCD (farrell2023closingthegap pages 1-2).

9. Inheritance and Population

Epidemiology

Prevalence: Lifetime prevalence across 10 countries in World Mental Health surveys is 4.1%, with 12-month prevalence of 3.0% (stein2025obsessivecompulsivedisorderin pages 1-2). Estimates from literature range from 1-3% of the general population (jalal2023obsessive‐compulsivedisorderetiology pages 1-2, strom2025genomewideanalysesidentify pages 1-2).

Incidence: Pediatric-onset OCD affects approximately 2-4% of children and adolescents (liu2023earlyidentificationand pages 1-2).

Inheritance Pattern

OCD demonstrates polygenic inheritance with moderate heritability. Twin-based heritability: 27-47% in adults, 45-65% in children (dhiman2025hereditarypatternsand pages 1-1, strom2025genomewideanalysesidentify pages 1-2). Family studies show OCD is more prevalent in first-degree relatives of affected individuals (farrell2023closingthegap pages 1-2).

Population Demographics

Age Distribution: Bimodal onset with peaks in adolescence (12-14 years) and young adulthood (20-22 years) (liu2023earlyidentificationand pages 1-2).

Sex Ratio: Available sources did not provide definitive male:female ratios.

Geographic Distribution: OCD appears cross-culturally prevalent with relatively consistent rates across high-income countries (HICs) and low-middle income countries (LMICs), though treatment rates are much higher in HICs (40.5%) than LMICs (7.0%) (stein2025obsessivecompulsivedisorderin pages 1-2).

10. Diagnostics

Clinical Criteria

DSM-5 Diagnostic Criteria: Presence of obsessions and/or compulsions that are time-consuming (>1 hour/day) and cause significant distress or functional impairment. Symptoms must not be attributable to other mental or physical disorders (jalal2023obsessive‐compulsivedisorderetiology pages 1-2).

Differential Diagnosis: Must distinguish from other obsessive-compulsive and related disorders, anxiety disorders, and psychotic disorders. Level of insight distinguishes OCD with poor/absent insight from primary psychotic illness (jalal2023obsessive‐compulsivedisorderetiology pages 1-2).

Clinical Tests

Severity Assessment: Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is the standard severity measure (stein2025obsessivecompulsivedisorderin pages 1-2).

Imaging Studies: Neuroimaging reveals functional abnormalities in CSTC circuits, particularly in orbitofrontal cortex, anterior cingulate cortex, striatum, and thalamus (jalal2023obsessive‐compulsivedisorderetiology pages 2-3). Both structural MRI and functional MRI demonstrate aberrant CSTC connectivity and activity (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Genetic Testing

While specific genes have been identified through GWAS, genetic testing is not currently part of routine clinical diagnosis given the highly polygenic architecture. Research applications include whole exome sequencing and genome-wide genotyping for risk prediction and mechanistic studies (strom2025genomewideanalysesidentify pages 1-2).

11. Outcome/Prognosis

Disease Course and Morbidity

OCD is highly persistent, with 12-month prevalence nearly matching lifetime prevalence (stein2025obsessivecompulsivedisorderin pages 1-2). The condition causes substantial functional impairment across academic, occupational, and social domains (farrell2023closingthegap pages 1-2). Childhood onset is associated with greater severity, more symptoms, and poorer prognosis than adult onset (farrell2023closingthegap pages 1-2).

Quality of Life

OCD is ranked among the leading causes of illness-related disability by the World Health Organization (roh2023clinicaladvancesin pages 1-2). The disorder significantly impacts daily functioning, with severe cases experiencing substantial disability in occupational and social domains (farrell2023closingthegap pages 1-2).

Treatment Response

Only 19.8% of respondents with OCD in World Mental Health surveys received any mental health treatment in the past year (stein2025obsessivecompulsivedisorderin pages 1-2). Approximately 50% of OCD patients do not respond adequately to initial treatments (huang2025advancingobsessive–compulsivedisorder pages 1-2). Treatment adherence during exposure and response prevention predicts both short-term and long-term outcomes (farrell2023closingthegap pages 1-2).

12. Treatment

Pharmacotherapy

First-Line: Selective serotonin reuptake inhibitors (SSRIs) including fluoxetine, sertraline, fluvoxamine, paroxetine, and escitalopram are considered first-line pharmacotherapy (roh2023clinicaladvancesin pages 1-2, huang2025advancingobsessive–compulsivedisorder pages 1-2). SSRIs modulate serotonergic neurotransmission and downstream CSTC circuit activity (roh2023clinicaladvancesin pages 1-2).

Augmentation: Atypical antipsychotics are used for augmentation in SSRI partial responders, particularly those with tic-related presentations (roh2023clinicaladvancesin pages 1-2).

Psychotherapy

Cognitive Behavioral Therapy with Exposure and Response Prevention (CBT-ERP): Gold-standard psychological treatment involving systematic exposure to obsessional triggers with prevention of compulsive responses (roh2023clinicaladvancesin pages 1-2, farrell2023closingthegap pages 1-2). CBT-ERP promotes inhibitory learning, fear extinction, and improved cognitive control (farrell2023closingthegap pages 1-2).

Treatment Modalities: Delivered through individual therapy, family-based approaches, group therapy, and internet-delivered formats. Intensive or concentrated ERP (over consecutive days) may be beneficial for severe or treatment-resistant cases (farrell2023closingthegap pages 1-2).

Advanced Therapeutics

Neuromodulation: Transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS) targeting CSTC circuit nodes are used for treatment-refractory OCD (roh2023clinicaladvancesin pages 1-2, huang2025advancingobsessive–compulsivedisorder pages 1-2).

Neurosurgical Interventions: Ablative procedures such as anterior cingulotomy are reserved for severe, treatment-refractory cases (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Treatment Strategy

Staged-care models match treatment intensity to illness severity, comorbidity burden, and prior treatment response. This approach aims to deliver "right care, first time" and close treatment gaps (farrell2023closingthegap pages 1-2).

Suggested MAXO Terms: - MAXO:0000011 (Psychotherapy) - MAXO:0000058 (Pharmacotherapy) - MAXO:0001298 (Cognitive behavioral therapy)

Treatment Category Specific Interventions Mechanism of Action Evidence Level Efficacy/Response Rates Key Citations
First-line psychotherapy Cognitive behavioral therapy with exposure and response prevention (CBT-ERP); individual, family-based, group, internet/digital, and staged-care CBT-ERP for youth Repeated, systematic exposure to obsessional triggers with prevention of rituals/avoidance; promotes inhibitory learning, fear extinction, reduced negative reinforcement, and improved cognitive control over compulsions High; described as gold-standard/first-line in recent reviews and guidelines Strong efficacy across adults and youth; not all patients remit, and a substantial minority remain symptomatic; pediatric review notes CBT-ERP is highly effective, though underused in practice; adherence during ERP predicts better short- and long-term outcomes (roh2023clinicaladvancesin pages 1-2, farrell2023closingthegap pages 1-2) (roh2023clinicaladvancesin pages 1-2, farrell2023closingthegap pages 1-2)
First-line pharmacotherapy Selective serotonin reuptake inhibitors (SSRIs): fluoxetine, sertraline, fluvoxamine, paroxetine, escitalopram/citalopram (class-level evidence emphasized) Block serotonin reuptake, increasing synaptic serotonin; downstream modulation of cortico-striato-thalamo-cortical (CSTC) circuit activity and symptom-related salience processing High; consistently recommended as first-line pharmacotherapy in adult OCD reviews Effective for many patients, but a large proportion show only partial response; one 2025 review cited in retrieved evidence notes ~50% may not respond adequately to standard treatments; SSRIs and CBT both reduce symptoms, with partly distinct neural effects and common reduction of insula activity during symptom provocation after treatment (roh2023clinicaladvancesin pages 1-2, huang2025advancingobsessive–compulsivedisorder pages 1-2) (roh2023clinicaladvancesin pages 1-2, huang2025advancingobsessive–compulsivedisorder pages 1-2)
Combined first-line treatment CBT-ERP plus SSRI, especially for moderate-severe illness, comorbidity, or partial response to monotherapy Combines behavioral extinction/response prevention with serotonergic modulation of CSTC dysfunction Moderate-high; recommended in treatment overviews and staged-care models Used when symptom burden, comorbidity, or prior treatment history justify escalation; recent pediatric staged-care framework recommends matching intensity to severity and previous response rather than one-size-fits-all care (roh2023clinicaladvancesin pages 1-2, farrell2023closingthegap pages 1-2) (roh2023clinicaladvancesin pages 1-2, farrell2023closingthegap pages 1-2)
Second-line / augmentation Atypical antipsychotic augmentation of SSRIs (class-level; e.g., risperidone/aripiprazole commonly referenced in OCD practice reviews), especially for SSRI partial responders or tic-related presentations Dopamine/serotonin receptor modulation; intended to reduce persistent compulsivity and augment SSRI effect in refractory CSTC dysfunction Moderate; recommended in adult treatment reviews as augmentation rather than monotherapy Useful in a subset of partial responders; evidence supports use after adequate SSRI trial and/or CBT failure rather than as initial treatment (roh2023clinicaladvancesin pages 1-2) (roh2023clinicaladvancesin pages 1-2)
Second-line / treatment optimization High-intensity or concentrated ERP; intensive outpatient/residential ERP; improving adherence and therapist fidelity Increases exposure dose, reduces accommodation/avoidance, and strengthens ritual prevention in severe or chronic cases Moderate; supported by clinical studies and service-model literature Treatment adherence predicts post-treatment, 3-month, and 1-year OCD severity and work/social functioning in difficult-to-treat cases, suggesting optimization of ERP delivery is a key modifiable lever (farrell2023closingthegap pages 1-2) (farrell2023closingthegap pages 1-2)
Novel / experimental neuromodulation Repetitive transcranial magnetic stimulation (TMS), including circuit-targeted stimulation approaches Noninvasive modulation of dysfunctional frontostriatal/CSTC activity, potentially affecting inhibition, salience, and compulsive motor patterns Emerging/moderate; highlighted in recent reviews as promising but not universally first-line Considered for refractory OCD; recent reviews frame TMS as a developing option alongside advances in neuroimaging/electrophysiology-guided personalization (roh2023clinicaladvancesin pages 1-2) (roh2023clinicaladvancesin pages 1-2)
Novel / experimental neuromodulation Deep brain stimulation (DBS) targeting CSTC-related nodes; ventral/striatal and related circuit targets discussed in recent reviews Direct electrical modulation of pathologic frontostriatal network dynamics in severe, treatment-refractory OCD Moderate for severe refractory illness; generally reserved for highly selected patients Used after failure of standard therapies; recent modeling/review work emphasizes frontostriatal circuit rebalancing as the conceptual basis for benefit (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3) (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Neurosurgical interventions Ablative neurosurgery/lesion procedures such as anterior cingulotomy or related psychosurgical approaches in extreme refractory cases Interrupts maladaptive CSTC loops implicated in persistent obsessions/compulsions Limited but established for rare, severe, otherwise intractable cases Historical and contemporary literature cited in recent reviews indicates symptom improvement can occur in carefully selected severe cases; reserved for last-resort use due to invasiveness (jalal2023obsessive‐compulsivedisorderetiology pages 2-3) (jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Treatment resistance approaches Personalized staged-care pathways; escalation based on severity, comorbidity, and prior treatment history; multimodal service design Matches treatment intensity to illness stage and complexity; aims to reduce undertreatment and delayed access Moderate; especially developed in pediatric OCD service literature Proposed to close the “treatment gap” and “quality gap”; youth OCD often experiences long delays to care, and staged models aim to deliver the least intrusive effective intervention first, escalating as needed (farrell2023closingthegap pages 1-2, liu2023earlyidentificationand pages 1-2) (farrell2023closingthegap pages 1-2, liu2023earlyidentificationand pages 1-2)
Treatment resistance approaches Mechanism-informed monitoring with imaging/brain-based biomarkers (research use), and circuit-informed intervention selection Uses neural signatures such as insula/frontostriatal activity to understand or predict response and tailor interventions Emerging/experimental 2024 longitudinal imaging study found CBT and SSRIs both reduced symptoms but produced partly divergent brain changes, with a common reduction in insula activity during symptom provocation; currently more useful mechanistically than diagnostically in routine care (roh2023clinicaladvancesin pages 1-2) (roh2023clinicaladvancesin pages 1-2)

Table: This table summarizes current OCD treatment strategies across first-line, second-line, experimental, and treatment-resistant settings. It highlights mechanisms, approximate evidence strength, and clinically relevant outcome patterns from recent reviews and studies.

13. Prevention

Secondary Prevention

Early identification and intervention in pediatric OCD is critical, as delayed treatment is associated with worse prognosis (liu2023earlyidentificationand pages 1-2). Interventions focus on preventing conversion of obsessive-compulsive symptoms into full-blown OCD (liu2023earlyidentificationand pages 1-2).

Tertiary Prevention

Focuses on alleviating mild to moderate OCD and preventing complications, though interventions for comorbidities remain in their infancy (liu2023earlyidentificationand pages 1-2).

Screening

Systematic screening programs for OCD are not currently widespread. The duration of untreated OCD remains among the highest of all psychiatric disorders, highlighting need for improved early detection (liu2023earlyidentificationand pages 1-2).

14. Other Species / Natural Disease

Limited information available in retrieved sources regarding naturally occurring OCD in other species.

15. Model Organisms

Genetic Models

Multiple transgenic mouse models have been developed to study OCD mechanisms (huang2025advancingobsessive–compulsivedisorder pages 1-2):

Key Mouse Models: - Hoxb8-KO: Excessive grooming/self-injury phenotype - Slc1a1-KO: Glutamatergic dysfunction model - Sapap3-KO: Well-established compulsive grooming model with corticostriatal synaptic abnormalities - Slitrk5-KO: Excessive grooming and anxiety-like behaviors - Spred2-KO: Repetitive grooming/compulsive-like behavior

Circuit Models

Optogenetic stimulation of orbitofrontal cortex-ventromedial striatum (OFC-VMS) connections can induce OCD-like grooming behaviors in mice, supporting the CSTC circuit model (jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Zebrafish Models

Zebrafish models with altered slitrk5a demonstrate OCD-like "checking" behaviors, useful for high-throughput screening (huang2025advancingobsessive–compulsivedisorder pages 1-2).

Model Limitations

No single model captures the full human OCD syndrome, particularly intrusive obsessions, symptom dimensions, fluctuating insight, and comorbidity patterns (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3).

Model Type Specific Model Name Species Genes Involved OCD-like Phenotypes Observed Brain Regions/Circuits Affected Utility/Applications Limitations
Genetic knockout Hoxb8-KO Mouse Hoxb8 Excessive grooming/self-injury–like repetitive behavior; compulsive grooming phenotype used as an OCD-relevant endophenotype Cortico-striato-thalamo-cortical (CSTC)-relevant circuitry broadly implicated; also linked to microglial/hematopoietic contributions rather than a single canonical OCD node (huang2025advancingobsessive–compulsivedisorder pages 1-2) Useful for studying repetitive grooming, neuroimmune contributions, and disentangling compulsive motor output from anxiety-like behaviors (huang2025advancingobsessive–compulsivedisorder pages 1-2) Face validity for grooming is strong, but limited construct validity for intrusive obsessions; captures only a subset of human OCD phenomenology (huang2025advancingobsessive–compulsivedisorder pages 1-2)
Genetic knockout Slc1a1-KO Mouse Slc1a1 / EAAT3 Repetitive/compulsive-like behaviors and anxiety-related phenotypes in an OCD risk-gene framework Glutamatergic signaling within CSTC-related circuits; striatum/cortex glutamate homeostasis is the main mechanistic relevance (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3) Useful for probing glutamatergic mechanisms and testing candidate glutamate-modulating interventions (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3) Human OCD is polygenic; single-gene knockout incompletely models symptom heterogeneity and cognitive obsessions (huang2025advancingobsessive–compulsivedisorder pages 1-2)
Genetic knockout Sapap3-KO Mouse Sapap3 / Dlgap3 Excessive grooming, anxiety-like behavior, repetitive acts; one of the best-established compulsive grooming models Corticostriatal synapses, especially striatal dysfunction within CSTC circuitry (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3) High translational value for corticostriatal synaptopathy, habit/compulsivity mechanisms, and rescue experiments with circuit or pharmacologic interventions (huang2025advancingobsessive–compulsivedisorder pages 1-2) Strong for compulsions/grooming but does not model intrusive obsessions or full symptom dimensions seen in humans (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Genetic knockout Slitrk5-KO Mouse Slitrk5 Excessive grooming and anxiety-like/compulsive-like behaviors Orbitofrontal-striatal and broader CSTC dysfunction relevant to compulsivity (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3) Useful for studying synaptogenesis-related mechanisms and corticostriatal abnormalities in OCD-like behavior (huang2025advancingobsessive–compulsivedisorder pages 1-2) Limited to a narrow behavioral phenotype; genetic effect sizes in humans are smaller and more polygenic than in knockout models (huang2025advancingobsessive–compulsivedisorder pages 1-2)
Genetic knockout Spred2-KO Mouse Spred2 Repetitive grooming/compulsive-like behavior in transgenic OCD modeling summaries CSTC-related signaling abnormalities; mechanistically linked to intracellular signaling regulation rather than a single OCD-specific node (huang2025advancingobsessive–compulsivedisorder pages 1-2) Useful for investigating intracellular signaling contributions to repetitive behavior and for comparative model selection across transgenic strains (huang2025advancingobsessive–compulsivedisorder pages 1-2) Less extensively validated than Sapap3-KO; uncertain breadth of translational relevance to diverse OCD symptom dimensions (huang2025advancingobsessive–compulsivedisorder pages 1-2)
Genetic/optogenetic circuit model Repeated OFC–VMS stimulation model Mouse Circuit perturbation model rather than a single gene Induced OCD-like grooming/compulsive behavior after repeated stimulation Orbitofrontal cortex (OFC) and ventromedial striatum (VMS) within CSTC loops (jalal2023obsessive‐compulsivedisorderetiology pages 2-3) Strong causal tool for testing whether abnormal CSTC activity can generate compulsive behaviors; valuable for circuit-level intervention studies (jalal2023obsessive‐compulsivedisorderetiology pages 2-3) Not a natural disease model; limited ecological validity and does not capture developmental/polygenic aspects of OCD (jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Transgenic model class Knockout mouse models (aggregate class reviewed in recent literature) Mouse Includes Hoxb8, Slc1a1, Sapap3, Slitrk5, Spred2 Repetitive grooming, anxiety-like behavior, compulsive-like rituals; model-specific variation Recurrently implicate CSTC circuits, especially orbitofrontal, striatal, and thalamic pathway abnormalities (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3) Comparative platform for selecting models by mechanism: synaptic, glutamatergic, signaling, or neuroimmune hypotheses; supports neuromodulation and drug development work (huang2025advancingobsessive–compulsivedisorder pages 1-2) No single model captures the full human syndrome, especially obsessions, symptom dimensions, fluctuating insight, and comorbidity (huang2025advancingobsessive–compulsivedisorder pages 1-2, jalal2023obsessive‐compulsivedisorderetiology pages 2-3)
Zebrafish genetic model slitrk5a altered zebrafish model Zebrafish slitrk5a “Checking”-like repetitive behavior reported as OCD-like in zebrafish model literature Vertebrate brain circuit analogs relevant to repetitive behavioral control; not directly homologous to mammalian CSTC architecture (huang2025advancingobsessive–compulsivedisorder pages 1-2) Useful for high-throughput genetics and drug screening, rapid developmental studies, and comparative validation of OCD risk genes (huang2025advancingobsessive–compulsivedisorder pages 1-2) Behavioral homology to human obsessions/compulsions is indirect; circuit correspondence to human OCD is limited (huang2025advancingobsessive–compulsivedisorder pages 1-2)
Other species/model note Zebrafish and other lower-animal OCD-relevant models (general mention) Zebrafish / lower vertebrates Varies by construct Repetitive/compulsive-like phenotypes are used as analog readouts Developmental and conserved neural pathway studies; not direct one-to-one CSTC replication (huang2025advancingobsessive–compulsivedisorder pages 1-2) Helpful for scalable screening and testing conserved gene-function effects across species (huang2025advancingobsessive–compulsivedisorder pages 1-2) Reduced face validity for complex human psychopathology, especially intrusive thoughts and higher-order cognition (huang2025advancingobsessive–compulsivedisorder pages 1-2)
Pharmacological / environmental models Not specified in the available OCD contexts Not specified Not specified Typically used in the field for repetitive behavior provocation, but no specific OCD pharmacological model was detailed in the available contexts Not specified in available contexts Can complement genetic models when available Not enough source detail in the available contexts to summarize specific models responsibly (huang2025advancingobsessive–compulsivedisorder pages 1-2)

Table: This table summarizes major animal models used in obsessive-compulsive disorder research, emphasizing transgenic mouse lines and zebrafish models mentioned in the available sources. It is useful for comparing each model’s phenotypes, implicated circuits, translational uses, and major limitations.


Summary

Obsessive-Compulsive Disorder is a common, chronic neuropsychiatric disorder affecting 1-3% of the population with onset typically in childhood, adolescence, or young adulthood. The condition demonstrates substantial heritability (27-47% in adults, 45-65% in children) with highly polygenic architecture involving thousands of genetic variants. The largest GWAS identified 30 genome-wide significant loci and prioritized key genes including WDR6, DALRD3, and CTNND1.

OCD pathophysiology centers on dysfunction in cortico-striato-thalamo-cortical (CSTC) circuits involving orbitofrontal cortex, anterior cingulate cortex, striatum, and thalamus, with dysregulation of serotonergic, dopaminergic, and glutamatergic neurotransmission. Genetic risk is enriched in excitatory neurons of hippocampus and cortex, and dopamine receptor-containing medium spiny neurons in striatum.

First-line treatments include cognitive behavioral therapy with exposure and response prevention (CBT-ERP) and selective serotonin reuptake inhibitors (SSRIs), though approximately 50% of patients show inadequate response to initial interventions. Novel treatments include neuromodulation (TMS, DBS) for refractory cases. Staged-care models aim to match treatment intensity to clinical severity and prior response.

OCD causes substantial functional impairment and disability, with only 19.8% of affected individuals receiving treatment in the past year globally. Early identification and intervention are critical, particularly in pediatric-onset cases which demonstrate higher genetic loading and potentially worse prognosis without adequate treatment.

References

  1. (jalal2023obsessive‐compulsivedisorderetiology pages 1-2): Baland Jalal, Samuel R. Chamberlain, and Barbara J. Sahakian. Obsessive‐compulsive disorder: etiology, neuropathology, and cognitive dysfunction. Brain and Behavior, May 2023. URL: https://doi.org/10.1002/brb3.3000, doi:10.1002/brb3.3000. This article has 162 citations and is from a peer-reviewed journal.

  2. (roh2023clinicaladvancesin pages 1-2): Daeyoung Roh, Ki Won Jang, and Chan-Hyung Kim. Clinical advances in treatment strategies for obsessive-compulsive disorder in adults. Clinical Psychopharmacology and Neuroscience, 21:676-685, Jul 2023. URL: https://doi.org/10.9758/cpn.23.1075, doi:10.9758/cpn.23.1075. This article has 29 citations.

  3. (stein2025obsessivecompulsivedisorderin pages 1-2): Dan J. Stein, Ayelet Meron Ruscio, Yasmin Altwaijri, Wai Tat Chiu, Nancy A. Sampson, Sergio Aguilar-Gaxiola, Ali Al-Hamzawi, Jordi Alonso, Stephanie Chardoul, Oye Gureje, Chiyi Hu, Elie G. Karam, John J. McGrath, Fernando Navarro-Mateu, Kate M. Scott, Juan Carlos Stagnaro, Yolanda Torres, Cristian Vladescu, Jacek Wciórka, Miguel Xavier, Ronald C. Kessler, Yasmin A. Altwaijri, Laura Helena Andrade, Lukoye Atwoli, Corina Benjet, Guilherme Borges, Ronny Bruffaerts, Brendan Bunting, Jose Miguel Caldas-de-Almeida, Graça Cardoso, Louisa Degenhardt, Giovanni de Girolamo, Josep Maria Haro, Meredith G. Harris, Hristo Hinkov, Chiyi Hu, Peter de Jonge, Aimee Nasser Karam, Georges Karam, Alan E. Kazdin, Norito Kawakami, Andrzej Kiejna, Viviane Kovess-Masfety, Maria Elena Medina-Mora, Jacek Moskalewicz, Daisuke Nishi, Marina Piazza, José Posada-Villa, Annelieke Roest, Margreet ten Have, Nathan Tintle, Maria Carmen Viana, Daniel V. Vigo, David R. Williams, Bogdan Wojtyniak, and Alan M. Zaslavsky. Obsessive-compulsive disorder in the world mental health surveys. BMC Medicine, Jul 2025. URL: https://doi.org/10.1186/s12916-025-04209-5, doi:10.1186/s12916-025-04209-5. This article has 41 citations and is from a domain leading peer-reviewed journal.

  4. (strom2025genomewideanalysesidentify pages 1-2): Nora I. Strom, Zachary F. Gerring, Marco Galimberti, Dongmei Yu, Matthew W. Halvorsen, Abdel Abdellaoui, Cristina Rodriguez-Fontenla, Julia M. Sealock, Tim Bigdeli, Jonathan R. Coleman, Behrang Mahjani, Jackson G. Thorp, Katharina Bey, Christie L. Burton, Jurjen J. Luykx, Gwyneth Zai, Silvia Alemany, Christine Andre, Kathleen D. Askland, Julia Bäckman, Nerisa Banaj, Cristina Barlassina, Judith Becker Nissen, O. Joseph Bienvenu, Donald Black, Michael H. Bloch, Sigrid Børte, Rosa Bosch, Michael Breen, Brian P. Brennan, Helena Brentani, Joseph D. Buxbaum, Jonas Bybjerg-Grauholm, Enda M. Byrne, Judit Cabana-Dominguez, Beatriz Camarena, Adrian Camarena, Carolina Cappi, Angel Carracedo, Miguel Casas, Maria Cristina Cavallini, Valentina Ciullo, Edwin H. Cook, Jesse Crosby, Bernadette A. Cullen, Elles J. De Schipper, Richard Delorme, Srdjan Djurovic, Jason A. Elias, Xavier Estivill, Martha J. Falkenstein, Bengt T. Fundin, Lauryn Garner, Christina Gironda, Fernando S. Goes, Marco A. Grados, Jakob Grove, Wei Guo, Jan Haavik, Kristen Hagen, Kelly Harrington, Alexandra Havdahl, Kira D. Höffler, Ana G. Hounie, Donald Hucks, Christina Hultman, Magdalena Janecka, Eric Jenike, Elinor K. Karlsson, Kara Kelley, Julia Klawohn, Janice E. Krasnow, Kristi Krebs, Christoph Lange, Nuria Lanzagorta, Daniel Levey, Kerstin Lindblad-Toh, Fabio Macciardi, Brion Maher, Brittany Mathes, Evonne McArthur, Nathaniel McGregor, Nicole C. McLaughlin, Sandra Meier, Euripedes C. Miguel, Maureen Mulhern, Paul S. Nestadt, Erika L. Nurmi, Kevin S. O’Connell, Lisa Osiecki, Olga Therese Ousdal, Teemu Palviainen, Nancy L. Pedersen, Fabrizio Piras, Federica Piras, Sriramya Potluri, Raquel Rabionet, Alfredo Ramirez, Scott Rauch, Abraham Reichenberg, Mark A. Riddle, Stephan Ripke, Maria C. Rosário, Aline S. Sampaio, Miriam A. Schiele, Anne Heidi Skogholt, Laura G. Sloofman, Jan Smit, María Soler Artigas, Laurent F. Thomas, Eric Tifft, Homero Vallada, Nathanial van Kirk, Jeremy Veenstra-VanderWeele, Nienke N. Vulink, Christopher P. Walker, Ying Wang, Jens R. Wendland, Bendik S. Winsvold, Yin Yao, Hang Zhou, Andres Metspalu, Tõnu Esko, Reedik Mägi, Mari Nelis, Georgi Hudjashov, Chris German, Arpana Agrawal, Pino Alonso, Götz Berberich, Kathleen K. Bucholz, Cynthia M. Bulik, Danielle Cath, Damiaan Denys, Valsamma Eapen, Howard Edenberg, Peter Falkai, Thomas V. Fernandez, Abby J. Fyer, J. M. Gaziano, Dan A. Geller, Hans J. Grabe, Benjamin D. Greenberg, Gregory L. Hanna, Ian B. Hickie, David M. Hougaard, Norbert Kathmann, James Kennedy, Dongbing Lai, Mikael Landén, Stéphanie Le Hellard, Marion Leboyer, Christine Lochner, James T. McCracken, Sarah E. Medland, Preben B. Mortensen, Benjamin M. Neale, Humberto Nicolini, Merete Nordentoft, Michele Pato, Carlos Pato, David L. Pauls, John Piacentini, Christopher Pittenger, Danielle Posthuma, Josep Antoni Ramos-Quiroga, Steven A. Rasmussen, Margaret A. Richter, David R. Rosenberg, Stephan Ruhrmann, Jack F. Samuels, Sven Sandin, Paul Sandor, Gianfranco Spalletta, Dan J. Stein, S. Evelyn Stewart, Eric A. Storch, Barbara E. Stranger, Maurizio Turiel, Thomas Werge, Ole A. Andreassen, Anders D. Børglum, Susanne Walitza, Kristian Hveem, Bjarne K. Hansen, Christian Rück, Nicholas G. Martin, Lili Milani, Ole Mors, Ted Reichborn-Kjennerud, Marta Ribasés, Gerd Kvale, David Mataix-Cols, Katharina Domschke, Edna Grünblatt, Michael Wagner, John-Anker Zwart, Gerome Breen, Gerald Nestadt, Jaakko Kaprio, Paul D. Arnold, Dorothy E. Grice, James A. Knowles, Helga Ask, Karin J. Verweij, Lea K. Davis, Dirk J. Smit, James J. Crowley, Jeremiah M. Scharf, Murray B. Stein, Joel Gelernter, Carol A. Mathews, Eske M. Derks, and Manuel Mattheisen. Genome-wide analyses identify 30 loci associated with obsessive–compulsive disorder. Nature Genetics, 57:1389-1401, May 2025. URL: https://doi.org/10.1038/s41588-025-02189-z, doi:10.1038/s41588-025-02189-z. This article has 70 citations and is from a highest quality peer-reviewed journal.

  5. (jalal2023obsessive‐compulsivedisorderetiology pages 2-3): Baland Jalal, Samuel R. Chamberlain, and Barbara J. Sahakian. Obsessive‐compulsive disorder: etiology, neuropathology, and cognitive dysfunction. Brain and Behavior, May 2023. URL: https://doi.org/10.1002/brb3.3000, doi:10.1002/brb3.3000. This article has 162 citations and is from a peer-reviewed journal.

  6. (dhiman2025hereditarypatternsand pages 1-1): Abhinay Dhiman, Sidharth Mehan, Zuber Khan, Aarti Tiwari, Ghanshyam Das Gupta, and Acharan Singh Narula. Hereditary patterns and genetic associations in obsessive-compulsive disorder (ocd): neuropsychiatric insights, genetic influences, and treatment perspectives. Mar 2025. URL: https://doi.org/10.2174/0115665232316708240828063527, doi:10.2174/0115665232316708240828063527. This article has 8 citations and is from a peer-reviewed journal.

  7. (liu2023earlyidentificationand pages 1-2): Xingyu Liu and Qing Fan. Early identification and intervention in pediatric obsessive-compulsive disorder. Brain Sciences, 13:399, Feb 2023. URL: https://doi.org/10.3390/brainsci13030399, doi:10.3390/brainsci13030399. This article has 25 citations.

  8. (strom2025genomewideanalysesidentify pages 2-3): Nora I. Strom, Zachary F. Gerring, Marco Galimberti, Dongmei Yu, Matthew W. Halvorsen, Abdel Abdellaoui, Cristina Rodriguez-Fontenla, Julia M. Sealock, Tim Bigdeli, Jonathan R. Coleman, Behrang Mahjani, Jackson G. Thorp, Katharina Bey, Christie L. Burton, Jurjen J. Luykx, Gwyneth Zai, Silvia Alemany, Christine Andre, Kathleen D. Askland, Julia Bäckman, Nerisa Banaj, Cristina Barlassina, Judith Becker Nissen, O. Joseph Bienvenu, Donald Black, Michael H. Bloch, Sigrid Børte, Rosa Bosch, Michael Breen, Brian P. Brennan, Helena Brentani, Joseph D. Buxbaum, Jonas Bybjerg-Grauholm, Enda M. Byrne, Judit Cabana-Dominguez, Beatriz Camarena, Adrian Camarena, Carolina Cappi, Angel Carracedo, Miguel Casas, Maria Cristina Cavallini, Valentina Ciullo, Edwin H. Cook, Jesse Crosby, Bernadette A. Cullen, Elles J. De Schipper, Richard Delorme, Srdjan Djurovic, Jason A. Elias, Xavier Estivill, Martha J. Falkenstein, Bengt T. Fundin, Lauryn Garner, Christina Gironda, Fernando S. Goes, Marco A. Grados, Jakob Grove, Wei Guo, Jan Haavik, Kristen Hagen, Kelly Harrington, Alexandra Havdahl, Kira D. Höffler, Ana G. Hounie, Donald Hucks, Christina Hultman, Magdalena Janecka, Eric Jenike, Elinor K. Karlsson, Kara Kelley, Julia Klawohn, Janice E. Krasnow, Kristi Krebs, Christoph Lange, Nuria Lanzagorta, Daniel Levey, Kerstin Lindblad-Toh, Fabio Macciardi, Brion Maher, Brittany Mathes, Evonne McArthur, Nathaniel McGregor, Nicole C. McLaughlin, Sandra Meier, Euripedes C. Miguel, Maureen Mulhern, Paul S. Nestadt, Erika L. Nurmi, Kevin S. O’Connell, Lisa Osiecki, Olga Therese Ousdal, Teemu Palviainen, Nancy L. Pedersen, Fabrizio Piras, Federica Piras, Sriramya Potluri, Raquel Rabionet, Alfredo Ramirez, Scott Rauch, Abraham Reichenberg, Mark A. Riddle, Stephan Ripke, Maria C. Rosário, Aline S. Sampaio, Miriam A. Schiele, Anne Heidi Skogholt, Laura G. Sloofman, Jan Smit, María Soler Artigas, Laurent F. Thomas, Eric Tifft, Homero Vallada, Nathanial van Kirk, Jeremy Veenstra-VanderWeele, Nienke N. Vulink, Christopher P. Walker, Ying Wang, Jens R. Wendland, Bendik S. Winsvold, Yin Yao, Hang Zhou, Andres Metspalu, Tõnu Esko, Reedik Mägi, Mari Nelis, Georgi Hudjashov, Chris German, Arpana Agrawal, Pino Alonso, Götz Berberich, Kathleen K. Bucholz, Cynthia M. Bulik, Danielle Cath, Damiaan Denys, Valsamma Eapen, Howard Edenberg, Peter Falkai, Thomas V. Fernandez, Abby J. Fyer, J. M. Gaziano, Dan A. Geller, Hans J. Grabe, Benjamin D. Greenberg, Gregory L. Hanna, Ian B. Hickie, David M. Hougaard, Norbert Kathmann, James Kennedy, Dongbing Lai, Mikael Landén, Stéphanie Le Hellard, Marion Leboyer, Christine Lochner, James T. McCracken, Sarah E. Medland, Preben B. Mortensen, Benjamin M. Neale, Humberto Nicolini, Merete Nordentoft, Michele Pato, Carlos Pato, David L. Pauls, John Piacentini, Christopher Pittenger, Danielle Posthuma, Josep Antoni Ramos-Quiroga, Steven A. Rasmussen, Margaret A. Richter, David R. Rosenberg, Stephan Ruhrmann, Jack F. Samuels, Sven Sandin, Paul Sandor, Gianfranco Spalletta, Dan J. Stein, S. Evelyn Stewart, Eric A. Storch, Barbara E. Stranger, Maurizio Turiel, Thomas Werge, Ole A. Andreassen, Anders D. Børglum, Susanne Walitza, Kristian Hveem, Bjarne K. Hansen, Christian Rück, Nicholas G. Martin, Lili Milani, Ole Mors, Ted Reichborn-Kjennerud, Marta Ribasés, Gerd Kvale, David Mataix-Cols, Katharina Domschke, Edna Grünblatt, Michael Wagner, John-Anker Zwart, Gerome Breen, Gerald Nestadt, Jaakko Kaprio, Paul D. Arnold, Dorothy E. Grice, James A. Knowles, Helga Ask, Karin J. Verweij, Lea K. Davis, Dirk J. Smit, James J. Crowley, Jeremiah M. Scharf, Murray B. Stein, Joel Gelernter, Carol A. Mathews, Eske M. Derks, and Manuel Mattheisen. Genome-wide analyses identify 30 loci associated with obsessive–compulsive disorder. Nature Genetics, 57:1389-1401, May 2025. URL: https://doi.org/10.1038/s41588-025-02189-z, doi:10.1038/s41588-025-02189-z. This article has 70 citations and is from a highest quality peer-reviewed journal.

  9. (strom2025genomewideanalysesidentify pages 3-4): Nora I. Strom, Zachary F. Gerring, Marco Galimberti, Dongmei Yu, Matthew W. Halvorsen, Abdel Abdellaoui, Cristina Rodriguez-Fontenla, Julia M. Sealock, Tim Bigdeli, Jonathan R. Coleman, Behrang Mahjani, Jackson G. Thorp, Katharina Bey, Christie L. Burton, Jurjen J. Luykx, Gwyneth Zai, Silvia Alemany, Christine Andre, Kathleen D. Askland, Julia Bäckman, Nerisa Banaj, Cristina Barlassina, Judith Becker Nissen, O. Joseph Bienvenu, Donald Black, Michael H. Bloch, Sigrid Børte, Rosa Bosch, Michael Breen, Brian P. Brennan, Helena Brentani, Joseph D. Buxbaum, Jonas Bybjerg-Grauholm, Enda M. Byrne, Judit Cabana-Dominguez, Beatriz Camarena, Adrian Camarena, Carolina Cappi, Angel Carracedo, Miguel Casas, Maria Cristina Cavallini, Valentina Ciullo, Edwin H. Cook, Jesse Crosby, Bernadette A. Cullen, Elles J. De Schipper, Richard Delorme, Srdjan Djurovic, Jason A. Elias, Xavier Estivill, Martha J. Falkenstein, Bengt T. Fundin, Lauryn Garner, Christina Gironda, Fernando S. Goes, Marco A. Grados, Jakob Grove, Wei Guo, Jan Haavik, Kristen Hagen, Kelly Harrington, Alexandra Havdahl, Kira D. Höffler, Ana G. Hounie, Donald Hucks, Christina Hultman, Magdalena Janecka, Eric Jenike, Elinor K. Karlsson, Kara Kelley, Julia Klawohn, Janice E. Krasnow, Kristi Krebs, Christoph Lange, Nuria Lanzagorta, Daniel Levey, Kerstin Lindblad-Toh, Fabio Macciardi, Brion Maher, Brittany Mathes, Evonne McArthur, Nathaniel McGregor, Nicole C. McLaughlin, Sandra Meier, Euripedes C. Miguel, Maureen Mulhern, Paul S. Nestadt, Erika L. Nurmi, Kevin S. O’Connell, Lisa Osiecki, Olga Therese Ousdal, Teemu Palviainen, Nancy L. Pedersen, Fabrizio Piras, Federica Piras, Sriramya Potluri, Raquel Rabionet, Alfredo Ramirez, Scott Rauch, Abraham Reichenberg, Mark A. Riddle, Stephan Ripke, Maria C. Rosário, Aline S. Sampaio, Miriam A. Schiele, Anne Heidi Skogholt, Laura G. Sloofman, Jan Smit, María Soler Artigas, Laurent F. Thomas, Eric Tifft, Homero Vallada, Nathanial van Kirk, Jeremy Veenstra-VanderWeele, Nienke N. Vulink, Christopher P. Walker, Ying Wang, Jens R. Wendland, Bendik S. Winsvold, Yin Yao, Hang Zhou, Andres Metspalu, Tõnu Esko, Reedik Mägi, Mari Nelis, Georgi Hudjashov, Chris German, Arpana Agrawal, Pino Alonso, Götz Berberich, Kathleen K. Bucholz, Cynthia M. Bulik, Danielle Cath, Damiaan Denys, Valsamma Eapen, Howard Edenberg, Peter Falkai, Thomas V. Fernandez, Abby J. Fyer, J. M. Gaziano, Dan A. Geller, Hans J. Grabe, Benjamin D. Greenberg, Gregory L. Hanna, Ian B. Hickie, David M. Hougaard, Norbert Kathmann, James Kennedy, Dongbing Lai, Mikael Landén, Stéphanie Le Hellard, Marion Leboyer, Christine Lochner, James T. McCracken, Sarah E. Medland, Preben B. Mortensen, Benjamin M. Neale, Humberto Nicolini, Merete Nordentoft, Michele Pato, Carlos Pato, David L. Pauls, John Piacentini, Christopher Pittenger, Danielle Posthuma, Josep Antoni Ramos-Quiroga, Steven A. Rasmussen, Margaret A. Richter, David R. Rosenberg, Stephan Ruhrmann, Jack F. Samuels, Sven Sandin, Paul Sandor, Gianfranco Spalletta, Dan J. Stein, S. Evelyn Stewart, Eric A. Storch, Barbara E. Stranger, Maurizio Turiel, Thomas Werge, Ole A. Andreassen, Anders D. Børglum, Susanne Walitza, Kristian Hveem, Bjarne K. Hansen, Christian Rück, Nicholas G. Martin, Lili Milani, Ole Mors, Ted Reichborn-Kjennerud, Marta Ribasés, Gerd Kvale, David Mataix-Cols, Katharina Domschke, Edna Grünblatt, Michael Wagner, John-Anker Zwart, Gerome Breen, Gerald Nestadt, Jaakko Kaprio, Paul D. Arnold, Dorothy E. Grice, James A. Knowles, Helga Ask, Karin J. Verweij, Lea K. Davis, Dirk J. Smit, James J. Crowley, Jeremiah M. Scharf, Murray B. Stein, Joel Gelernter, Carol A. Mathews, Eske M. Derks, and Manuel Mattheisen. Genome-wide analyses identify 30 loci associated with obsessive–compulsive disorder. Nature Genetics, 57:1389-1401, May 2025. URL: https://doi.org/10.1038/s41588-025-02189-z, doi:10.1038/s41588-025-02189-z. This article has 70 citations and is from a highest quality peer-reviewed journal.

  10. (farrell2023closingthegap pages 1-2): Lara J. Farrell, Allison M. Waters, Eric A. Storch, Gabrielle Simcock, Iain E. Perkes, Jessica R. Grisham, Katelyn M. Dyason, and Thomas H. Ollendick. Closing the gap for children with ocd: a staged-care model of cognitive behavioural therapy with exposure and response prevention. Clinical Child and Family Psychology Review, 26:642-664, Jul 2023. URL: https://doi.org/10.1007/s10567-023-00439-2, doi:10.1007/s10567-023-00439-2. This article has 32 citations and is from a domain leading peer-reviewed journal.

  11. (huang2025advancingobsessive–compulsivedisorder pages 1-2): Xinyuejia Huang, Linglong Xiao, Mengqi Wang, Yang Wu, Hao Deng, and Wei Wang. Advancing obsessive–compulsive disorder research: insights from transgenic animal models and innovative therapies. Brain Sciences, 15:43, Jan 2025. URL: https://doi.org/10.3390/brainsci15010043, doi:10.3390/brainsci15010043. This article has 1 citations.

Artifacts