FICUS syndrome - Disorder Mechanisms

●

Phenotypes

14

Nervous System(11) Constitutional(3)

Nervous System 11

Anxiety symptoms Anxiety (HP:0000739)

Show evidence (1 reference)

DOI:10.1038/s41598-024-53968-3 SUPPORT

"The prevalence of anxiety symptoms, depression, and posttraumatic stress disorder (PTSD) was higher in families of patients diagnosed with ICU delirium within 48 h of admission to the ICU."

This statement directly reports anxiety symptoms in family members of ICU patients.

Depressive symptoms Depression (HP:0000716)

Show evidence (1 reference)

DOI:10.1055/s-0043-1769933 SUPPORT

"The symptoms of anxiety were present in 44/84 (52.4%), and depression was present in 57/84 (67.9%) family members."

This documents depressive symptoms in ICU family members.

Posttraumatic stress symptoms Posttraumatic stress symptom (HP:0033676)

Show evidence (1 reference)

DOI:10.1038/s41598-024-53968-3 SUPPORT

"The prevalence of anxiety symptoms, depression, and posttraumatic stress disorder (PTSD) was higher in families of patients diagnosed with ICU delirium within 48 h of admission to the ICU."

This indicates PTSD-related symptoms in family members during ICU admission.

Anger Anger (HP:0031473)

Show evidence (1 reference)

DOI:10.1038/s41598-024-53968-3 PARTIAL

"Taking appropriate actions and thus providing families with appropriate support will contribute to the understanding of unfavorable emotional states, including anxiety, stress, depression, anger, agitation, or avoidance."

This statement lists anger among emotional states experienced by ICU family members.

Agitation Agitation (HP:0000713)

Show evidence (1 reference)

DOI:10.1038/s41598-024-53968-3 PARTIAL

"Taking appropriate actions and thus providing families with appropriate support will contribute to the understanding of unfavorable emotional states, including anxiety, stress, depression, anger, agitation, or avoidance."

This statement lists agitation among emotional states experienced by ICU family members.

Avoidance of stimuli associated with traumatic event Avoidance of stimuli associated with traumatic event (HP:0032942)

Show evidence (1 reference)

DOI:10.1038/s41598-024-53968-3 PARTIAL

"Taking appropriate actions and thus providing families with appropriate support will contribute to the understanding of unfavorable emotional states, including anxiety, stress, depression, anger, agitation, or avoidance."

This statement explicitly mentions avoidance as an emotional response in ICU family members.

Abnormal fear-induced behavior Abnormal fear-induced behavior (HP:0100852)

Show evidence (1 reference)

DOI:10.1055/s-0043-1769933 PARTIAL

"The common feelings of all the interviewees were desperation and fear."

Family members described fear during the ICU process, consistent with abnormal fear-related behavior.

Sleep disturbance Sleep disturbance (HP:0002360)

Show evidence (1 reference)

PMID:40161896 PARTIAL

"The sleep disturbances, fatigue, anxiety, and depression were assessed using the Pittsburgh Sleep Quality Index, the Subscale of Fatigue Assessment Instrument, and the Hospital Anxiety and Depression Scale, respectively."

This PICS-F study identifies sleep disturbance as a key symptom domain assessed in ICU family members.

Memory impairment Memory impairment (HP:0002354)

Show evidence (1 reference)

DOI:10.1055/s-0043-1769933 PARTIAL

"All interviewees stated having difficulty understanding and remembering what was told."

Family members reported difficulty remembering information during the ICU process, consistent with memory impairment.

Recurrent, involuntary, and intrusive distressing memories Recurrent, involuntary, and intrusive distressing memories (HP:0032937)

Show evidence (1 reference)

PMID:39023049 PARTIAL

"Tendencies to view the patient's death as unexpected may contribute to intrusive thoughts and memories of the ICU experience."

This describes intrusive thoughts and memories in ICU family caregivers, matching intrusive distressing memories.

Hopelessness Hopelessness (HP:5200271)

Show evidence (1 reference)

DOI:10.1055/s-0043-1769933 PARTIAL

"The common feelings of all the interviewees were desperation and fear."

Desperation aligns with hopelessness reported by ICU family members.

Constitutional 3

Fatigue Fatigue (HP:0012378)

Show evidence (1 reference)

PMID:40161896 PARTIAL

"The sleep disturbances, fatigue, anxiety, and depression were assessed using the Pittsburgh Sleep Quality Index, the Subscale of Fatigue Assessment Instrument, and the Hospital Anxiety and Depression Scale, respectively."

This PICS-F study includes fatigue as a key symptom domain in ICU family members.

Diminished health-related quality of life Diminished health-related quality of life (HP:0033665)

Show evidence (1 reference)

DOI:10.1186/s13613-025-01420-8 SUPPORT

"Almost one-third of the family members of ICU survivors reported persistent psychological symptoms and QoL problems at 12-months."

This supports diminished health-related quality of life in family members after ICU discharge.

Pain Pain (HP:0012531)

Show evidence (1 reference)

DOI:10.1186/s13613-025-01420-8 PARTIAL

"> 30% reported problems in pain/discomfort or anxiety/depression domains at 12-months."

This indicates pain/discomfort problems reported by ICU family members at 12 months.

💊

Treatments

1

Family support intervention MAXO:0000077

Nurse-led, interprofessional family support intervention aimed at improving family management, quality of care, and mental health for ICU family members.

Show evidence (1 reference)

DOI:10.1186/s13063-024-08351-y SUPPORT

"The FICUS trial is a cluster-randomized superiority trial to determine the effectiveness of a nurse-led, interprofessional family support intervention (FSI) on the quality of care, family management and individual mental health of family members of critically ill patients, compared to usual care."

This describes a structured family support intervention targeting mental health outcomes.

🌍

Environmental Factors

1

ICU admission exposure and family stressor

ICU admission and exposure to critical illness in a close family member act as a major psychosocial stressor for relatives.

Show evidence (3 references)

DOI:10.1038/s41598-024-53968-3 SUPPORT

"During intensive care unit admission, relatives of critically ill patients can experience emotional distress."

ICU admission is directly associated with emotional distress in family members, reflecting the environmental stressor context.

PMID:29277171 SUPPORT

"Family members of critically ill patients can suffer symptoms of post-intensive care syndrome-family (PICS-F), including anxiety, depression, and posttraumatic stress disorder (PTSD) with a diminished quality of life."

This explicitly links ICU patient critical illness to family psychological symptoms, supporting the ICU exposure stressor context.

PMID:35795400 SUPPORT

"PICS-F refers to the psychologic distress such as anxiety, depression, and posttraumatic stress disorder (PTSD) experienced by the patient's family."

This defines family psychological distress tied to ICU patient illness, reinforcing ICU exposure as a key environmental stressor.

🔀

Differential Diagnoses

3

Conditions with similar clinical presentations that must be differentiated from FICUS syndrome:

Post-traumatic stress disorder Not Yet Curated MONDO:0005146

Overlapping Features Psychiatric disorder characterized by intrusive memories, avoidance, negative mood/cognition changes, and hyperarousal after trauma exposure.

Distinguishing Features

PTSD is a formal trauma-related psychiatric diagnosis; FICUS is a syndrome tied to ICU family caregiving context.
PTSD may occur without the broader multi-domain family-caregiving context captured in FICUS.

Show evidence (1 reference)

PMID:30950647 SUPPORT

"The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."

This review documents PTSD prevalence in ICU family caregivers, supporting consideration of PTSD as a differential.

Major depressive disorder MONDO:0002009

Overlapping Features Depressive disorder characterized by persistent low mood, anhedonia, and functional impairment not necessarily linked to ICU caregiving.

Distinguishing Features

MDD can occur independent of ICU exposure, whereas FICUS is defined by the ICU family context.
FICUS often includes multiple symptom domains beyond depression alone.

Show evidence (1 reference)

PMID:30950647 SUPPORT

"The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."

The review shows depression is common in ICU family caregivers, motivating differential consideration with MDD.

Generalized anxiety disorder MONDO:0001942

Overlapping Features Anxiety disorder with excessive, persistent worry across domains, distinct from context-specific ICU caregiver stress.

Distinguishing Features

GAD is a chronic anxiety disorder that can predate ICU exposure.
FICUS-related anxiety is situational and tied to the ICU caregiving context.

Show evidence (1 reference)

PMID:30950647 SUPPORT

"The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."

The review reports anxiety prevalence in ICU family caregivers, supporting GAD as a differential diagnosis.

🔬

Clinical Trials

4

NCT05280691

Cluster-randomized superiority trial of a multicomponent, nurse-led family support intervention in adult intensive care units.

Show evidence (1 reference)

clinicaltrials:NCT05280691 SUPPORT

"The primary study endpoint is quality of family care, operationalized as family members' satisfaction with ICU care at discharge."

This trial evaluates a family support intervention and targets family outcomes relevant to FICUS.

NCT04316767

Pilot study of a smartphone self-care app delivering cognitive behavioral therapy to reduce psychological symptoms in ICU family members.

Show evidence (1 reference)

clinicaltrials:NCT04316767 SUPPORT

"This study will examine the effectiveness of a smartphone self-care app delivering cognitive behavioral therapy in decreasing the psychological symptoms suffered by ICU family members."

This trial targets psychological symptoms in ICU family members using a CBT-based intervention.

NCT04839406

Randomized controlled trial of a systematic follow-up intervention for caregivers of critically ill patients over 12 months.

Show evidence (1 reference)

clinicaltrials:NCT04839406 SUPPORT

"The aim of the project is to test the efficacy of a systematic intervention for individual follow-up of caregivers at the intensive care unit during a 12 month randomized controlled trial."

This trial evaluates an ICU caregiver follow-up intervention aligned with FICUS care needs.

NCT07228299

Multicenter RCT evaluating chaplain-delivered spiritual care for ICU family surrogates using the SCAI framework.

Show evidence (1 reference)

clinicaltrials:NCT07228299 SUPPORT

"The overarching goal of our work is to test the effect of high-quality spiritual care for ICU family surrogates on outcomes of psychological and spiritual well-being and medical decision making."

This trial targets psychological and spiritual outcomes in ICU family surrogates, relevant to FICUS.

{ }

Source YAML

click to show

name: FICUS syndrome
creation_date: '2026-01-26T17:51:15Z'
updated_date: '2026-02-16T20:19:38Z'
category: Psychiatric
description: >
  This entry describes the psychiatric PICS-F concept in ICU family members.
  Note: MONDO:0978296 refers to a genetic dysmorphology syndrome (OMIM 621193),
  not the PICS-F condition described here.
parents:
- Psychiatric Disease
prevalence:
- population: ICU family members of COVID-19 patients (single-center, Japan)
  percentage: 33
  evidence:
  - reference: PMID:35795400
    supports: SUPPORT
    snippet: "Overall PICS-F occurred in 33%."
    explanation: This study reports overall PICS-F occurrence among ICU family members of COVID-19 patients.
- population: Family decision-makers of critically ill patients (single-center, United States)
  percentage: 45.8
  evidence:
  - reference: PMID:29277171
    supports: PARTIAL
    snippet: "We found a significant prevalence of anxiety (45.8%), depression (25%), and PTSD (11.1%) symptoms among FDMs over the course of the study."
    explanation: This provides symptom prevalence estimates in family decision-makers during and after ICU admission.
epidemiology:
- name: Prevalence range of psychological outcomes in ICU family caregivers
  description: >
    Systematic review reporting wide ranges in prevalence estimates for
    depression, anxiety, and PTSD among family caregivers of critically ill
    ICU patients across studies.
  minimum_value: 2
  maximum_value: 94
  unit: percentage
  notes: Ranges reported across included studies; depression 4%–94%, anxiety 2%–80%, PTSD 3%–62%.
  evidence:
  - reference: PMID:30950647
    supports: SUPPORT
    snippet: "The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."
    explanation: This provides prevalence ranges across studies for key psychological outcomes in ICU family caregivers.
- name: Risk factors for psychological outcomes in ICU family caregivers
  description: >
    Systematic review identifying common risk factors for adverse psychological
    outcomes among family caregivers of critically ill ICU patients.
  factors:
  - Younger caregiver age
  - Caregiver relationship to the patient
  - Lower socioeconomic status
  - Female sex
  evidence:
  - reference: PMID:30950647
    supports: SUPPORT
    snippet: "Common risk factors identified for adverse psychological outcomes included younger caregiver age, caregiver relationship to the patient, lower socioeconomic status, and female sex."
    explanation: This review lists common risk factors associated with psychological outcomes in ICU family caregivers.
pathophysiology: []
phenotypes:
- name: Anxiety symptoms
  category: Psychiatric
  phenotype_term:
    preferred_term: Anxiety
    term:
      id: HP:0000739
      label: Anxiety
  evidence:
  - reference: DOI:10.1038/s41598-024-53968-3
    supports: SUPPORT
    snippet: "The prevalence of anxiety symptoms, depression, and posttraumatic stress disorder (PTSD) was higher in families of patients diagnosed with ICU delirium within 48 h of admission to the ICU."
    explanation: This statement directly reports anxiety symptoms in family members of ICU patients.
- name: Depressive symptoms
  category: Psychiatric
  phenotype_term:
    preferred_term: Depression
    term:
      id: HP:0000716
      label: Depression
  evidence:
  - reference: DOI:10.1055/s-0043-1769933
    supports: SUPPORT
    snippet: "The symptoms of anxiety were present in 44/84 (52.4%), and depression was present in 57/84 (67.9%) family members."
    explanation: This documents depressive symptoms in ICU family members.
- name: Posttraumatic stress symptoms
  category: Psychiatric
  phenotype_term:
    preferred_term: Posttraumatic stress symptom
    term:
      id: HP:0033676
      label: Posttraumatic stress symptom
  evidence:
  - reference: DOI:10.1038/s41598-024-53968-3
    supports: SUPPORT
    snippet: "The prevalence of anxiety symptoms, depression, and posttraumatic stress disorder (PTSD) was higher in families of patients diagnosed with ICU delirium within 48 h of admission to the ICU."
    explanation: This indicates PTSD-related symptoms in family members during ICU admission.
- name: Anger
  category: Psychiatric
  phenotype_term:
    preferred_term: Anger
    term:
      id: HP:0031473
      label: Anger
  evidence:
  - reference: DOI:10.1038/s41598-024-53968-3
    supports: PARTIAL
    snippet: "Taking appropriate actions and thus providing families with appropriate support will contribute to the understanding of unfavorable emotional states, including anxiety, stress, depression, anger, agitation, or avoidance."
    explanation: This statement lists anger among emotional states experienced by ICU family members.
- name: Agitation
  category: Psychiatric
  phenotype_term:
    preferred_term: Agitation
    term:
      id: HP:0000713
      label: Agitation
  evidence:
  - reference: DOI:10.1038/s41598-024-53968-3
    supports: PARTIAL
    snippet: "Taking appropriate actions and thus providing families with appropriate support will contribute to the understanding of unfavorable emotional states, including anxiety, stress, depression, anger, agitation, or avoidance."
    explanation: This statement lists agitation among emotional states experienced by ICU family members.
- name: Avoidance of stimuli associated with traumatic event
  category: Psychiatric
  phenotype_term:
    preferred_term: Avoidance of stimuli associated with traumatic event
    term:
      id: HP:0032942
      label: Avoidance of stimuli associated with traumatic event
  evidence:
  - reference: DOI:10.1038/s41598-024-53968-3
    supports: PARTIAL
    snippet: "Taking appropriate actions and thus providing families with appropriate support will contribute to the understanding of unfavorable emotional states, including anxiety, stress, depression, anger, agitation, or avoidance."
    explanation: This statement explicitly mentions avoidance as an emotional response in ICU family members.
- name: Abnormal fear-induced behavior
  category: Psychiatric
  phenotype_term:
    preferred_term: Abnormal fear-induced behavior
    term:
      id: HP:0100852
      label: Abnormal fear-induced behavior
  evidence:
  - reference: DOI:10.1055/s-0043-1769933
    supports: PARTIAL
    snippet: "The common feelings of all the interviewees were desperation and fear."
    explanation: Family members described fear during the ICU process, consistent with abnormal fear-related behavior.
- name: Sleep disturbance
  category: Psychiatric
  phenotype_term:
    preferred_term: Sleep disturbance
    term:
      id: HP:0002360
      label: Sleep disturbance
  evidence:
  - reference: PMID:40161896
    supports: PARTIAL
    snippet: "The sleep disturbances, fatigue, anxiety, and depression were assessed using the Pittsburgh Sleep Quality Index, the Subscale of Fatigue Assessment Instrument, and the Hospital Anxiety and Depression Scale, respectively."
    explanation: This PICS-F study identifies sleep disturbance as a key symptom domain assessed in ICU family members.
- name: Fatigue
  category: Systemic
  phenotype_term:
    preferred_term: Fatigue
    term:
      id: HP:0012378
      label: Fatigue
  evidence:
  - reference: PMID:40161896
    supports: PARTIAL
    snippet: "The sleep disturbances, fatigue, anxiety, and depression were assessed using the Pittsburgh Sleep Quality Index, the Subscale of Fatigue Assessment Instrument, and the Hospital Anxiety and Depression Scale, respectively."
    explanation: This PICS-F study includes fatigue as a key symptom domain in ICU family members.
- name: Memory impairment
  category: Neurological
  phenotype_term:
    preferred_term: Memory impairment
    term:
      id: HP:0002354
      label: Memory impairment
  evidence:
  - reference: DOI:10.1055/s-0043-1769933
    supports: PARTIAL
    snippet: "All interviewees stated having difficulty understanding and remembering what was told."
    explanation: Family members reported difficulty remembering information during the ICU process, consistent with memory impairment.
- name: Recurrent, involuntary, and intrusive distressing memories
  category: Psychiatric
  phenotype_term:
    preferred_term: Recurrent, involuntary, and intrusive distressing memories
    term:
      id: HP:0032937
      label: Recurrent, involuntary, and intrusive distressing memories
  evidence:
  - reference: PMID:39023049
    supports: PARTIAL
    snippet: "Tendencies to view the patient's death as unexpected may contribute to intrusive thoughts and memories of the ICU experience."
    explanation: This describes intrusive thoughts and memories in ICU family caregivers, matching intrusive distressing memories.
- name: Hopelessness
  category: Psychiatric
  phenotype_term:
    preferred_term: Hopelessness
    term:
      id: HP:5200271
      label: Hopelessness
  evidence:
  - reference: DOI:10.1055/s-0043-1769933
    supports: PARTIAL
    snippet: "The common feelings of all the interviewees were desperation and fear."
    explanation: Desperation aligns with hopelessness reported by ICU family members.
- name: Diminished health-related quality of life
  category: Systemic
  phenotype_term:
    preferred_term: Diminished health-related quality of life
    term:
      id: HP:0033665
      label: Diminished health-related quality of life
  evidence:
  - reference: DOI:10.1186/s13613-025-01420-8
    supports: SUPPORT
    snippet: "Almost one-third of the family members of ICU survivors reported persistent psychological symptoms and QoL problems at 12-months."
    explanation: This supports diminished health-related quality of life in family members after ICU discharge.
- name: Pain
  category: Systemic
  phenotype_term:
    preferred_term: Pain
    term:
      id: HP:0012531
      label: Pain
  evidence:
  - reference: DOI:10.1186/s13613-025-01420-8
    supports: PARTIAL
    snippet: "> 30% reported problems in pain/discomfort or anxiety/depression domains at 12-months."
    explanation: This indicates pain/discomfort problems reported by ICU family members at 12 months.
biochemical: []
genetic: []
environmental:
- name: ICU admission exposure and family stressor
  description: >
    ICU admission and exposure to critical illness in a close family member
    act as a major psychosocial stressor for relatives.
  evidence:
  - reference: DOI:10.1038/s41598-024-53968-3
    supports: SUPPORT
    snippet: "During intensive care unit admission, relatives of critically ill patients can experience emotional distress."
    explanation: ICU admission is directly associated with emotional distress in family members, reflecting the environmental stressor context.
  - reference: PMID:29277171
    supports: SUPPORT
    snippet: "Family members of critically ill patients can suffer symptoms of post-intensive care syndrome-family (PICS-F), including anxiety, depression, and posttraumatic stress disorder (PTSD) with a diminished quality of life."
    explanation: This explicitly links ICU patient critical illness to family psychological symptoms, supporting the ICU exposure stressor context.
  - reference: PMID:35795400
    supports: SUPPORT
    snippet: "PICS-F refers to the psychologic distress such as anxiety, depression, and posttraumatic stress disorder (PTSD) experienced by the patient's family."
    explanation: This defines family psychological distress tied to ICU patient illness, reinforcing ICU exposure as a key environmental stressor.
treatments:
- name: Family support intervention
  description: >
    Nurse-led, interprofessional family support intervention aimed at improving
    family management, quality of care, and mental health for ICU family members.
  evidence:
  - reference: DOI:10.1186/s13063-024-08351-y
    supports: SUPPORT
    snippet: "The FICUS trial is a cluster-randomized superiority trial to determine the effectiveness of a nurse-led, interprofessional family support intervention (FSI) on the quality of care, family management and individual mental health of family members of critically ill patients, compared to usual care."
    explanation: This describes a structured family support intervention targeting mental health outcomes.
  treatment_term:
    preferred_term: behavioral counseling
    term:
      id: MAXO:0000077
      label: behavioral counseling
datasets: []
clinical_trials:
- name: NCT05280691
  description: >
    Cluster-randomized superiority trial of a multicomponent, nurse-led family
    support intervention in adult intensive care units.
  evidence:
  - reference: clinicaltrials:NCT05280691
    supports: SUPPORT
    snippet: "The primary study endpoint is quality of family care, operationalized as family members' satisfaction with ICU care at discharge."
    explanation: This trial evaluates a family support intervention and targets family outcomes relevant to FICUS.
- name: NCT04316767
  description: >
    Pilot study of a smartphone self-care app delivering cognitive behavioral
    therapy to reduce psychological symptoms in ICU family members.
  evidence:
  - reference: clinicaltrials:NCT04316767
    supports: SUPPORT
    snippet: "This study will examine the effectiveness of a smartphone self-care app delivering cognitive behavioral therapy in decreasing the psychological symptoms suffered by ICU family members."
    explanation: This trial targets psychological symptoms in ICU family members using a CBT-based intervention.
- name: NCT04839406
  description: >
    Randomized controlled trial of a systematic follow-up intervention for
    caregivers of critically ill patients over 12 months.
  evidence:
  - reference: clinicaltrials:NCT04839406
    supports: SUPPORT
    snippet: "The aim of the project is to test the efficacy of a systematic intervention for individual follow-up of caregivers at the intensive care unit during a 12 month randomized controlled trial."
    explanation: This trial evaluates an ICU caregiver follow-up intervention aligned with FICUS care needs.
- name: NCT07228299
  description: >
    Multicenter RCT evaluating chaplain-delivered spiritual care for ICU family
    surrogates using the SCAI framework.
  evidence:
  - reference: clinicaltrials:NCT07228299
    supports: SUPPORT
    snippet: "The overarching goal of our work is to test the effect of high-quality spiritual care for ICU family surrogates on outcomes of psychological and spiritual well-being and medical decision making."
    explanation: This trial targets psychological and spiritual outcomes in ICU family surrogates, relevant to FICUS.

differential_diagnoses:
- name: Post-traumatic stress disorder
  disease_term:
    preferred_term: post-traumatic stress disorder
    term:
      id: MONDO:0005146
      label: post-traumatic stress disorder
  description: >
    Psychiatric disorder characterized by intrusive memories, avoidance,
    negative mood/cognition changes, and hyperarousal after trauma exposure.
  distinguishing_features:
  - PTSD is a formal trauma-related psychiatric diagnosis; FICUS is a syndrome tied to ICU family caregiving context.
  - PTSD may occur without the broader multi-domain family-caregiving context captured in FICUS.
  evidence:
  - reference: PMID:30950647
    supports: SUPPORT
    snippet: "The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."
    explanation: This review documents PTSD prevalence in ICU family caregivers, supporting consideration of PTSD as a differential.
- name: Major depressive disorder
  disease_term:
    preferred_term: major depressive disorder
    term:
      id: MONDO:0002009
      label: major depressive disorder
  description: >
    Depressive disorder characterized by persistent low mood, anhedonia,
    and functional impairment not necessarily linked to ICU caregiving.
  distinguishing_features:
  - MDD can occur independent of ICU exposure, whereas FICUS is defined by the ICU family context.
  - FICUS often includes multiple symptom domains beyond depression alone.
  evidence:
  - reference: PMID:30950647
    supports: SUPPORT
    snippet: "The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."
    explanation: The review shows depression is common in ICU family caregivers, motivating differential consideration with MDD.
- name: Generalized anxiety disorder
  disease_term:
    preferred_term: generalized anxiety disorder
    term:
      id: MONDO:0001942
      label: generalized anxiety disorder
  description: >
    Anxiety disorder with excessive, persistent worry across domains,
    distinct from context-specific ICU caregiver stress.
  distinguishing_features:
  - GAD is a chronic anxiety disorder that can predate ICU exposure.
  - FICUS-related anxiety is situational and tied to the ICU caregiving context.
  evidence:
  - reference: PMID:30950647
    supports: SUPPORT
    snippet: "The prevalence of psychological outcomes in family caregivers ranged from 4% to 94% for depression, 2% to 80% for anxiety, and 3% to 62% for PTSD."
    explanation: The review reports anxiety prevalence in ICU family caregivers, supporting GAD as a differential diagnosis.