How do you assess for a depressive episode in a psychiatric patient?

How to Assess for a Depressive Episode in a Psychiatric Patient

Begin with Immediate Safety Assessment

Before any formal depression assessment, immediately evaluate for risk of harm to self or others, severe agitation, psychosis, or confusion (delirium), as any of these require immediate psychiatric or emergency referral. 1, 2, 3

• Assess both active and passive suicidal ideation, including thoughts of suicide or death 3
• Severe agitation warrants urgent psychiatric evaluation 2
• Psychosis requires immediate psychiatric consultation 2
• Confusion or delirium demands immediate medical evaluation to rule out organic causes 2

Rule Out Medical and Substance-Induced Causes

Medical conditions and substances must be identified and treated before diagnosing primary depression, as many conditions can mimic or cause depressive symptoms. 2, 3

• Neurological causes: Evaluate for stroke, traumatic brain injury, CNS infections, CNS malignancies, seizure disorders, and neurodegenerative diseases 2
• Metabolic/endocrine disturbances: Check for hypoglycemia, hyponatremia, hypocalcemia, and thyroid disorders 2
• Substance-induced causes: Review medication side effects, drug intoxication, and withdrawal states 2, 3
• Distinguish organic from psychiatric presentation: Post-stroke aprosodic speech or flat affect from neurological damage can mimic depression but requires different treatment 2
• Fluctuating presentation suggests delirium rather than primary mood disorder 2

Establish Diagnosis Using DSM-5 Criteria

The diagnosis of a major depressive episode must be made through clinical evaluation based on DSM-5 criteria, which can be accomplished through standard clinical interview or structured assessment tools. 1

A major depressive episode requires:

• Prominent and relatively persistent depressed or dysphoric mood that interferes with daily functioning (nearly every day for at least 2 weeks) 4, 5
• At least 5 of the following 9 symptoms: depressed mood, loss of interest in usual activities, significant change in weight/appetite, insomnia or hypersomnia, psychomotor agitation or retardation, increased fatigue, feelings of guilt or worthlessness, slowed thinking or impaired concentration, suicide attempt or suicidal ideation 5

Structured diagnostic tools include:

• Structured Clinical Interview for DSM (SCID) 1
• Mini International Neuropsychiatric Interview (MINI) 1
• Schedule for Affective Disorders and Schizophrenia 1

Use Standardized Severity Assessment Tools

Administer the PHQ-9 as the primary screening and severity assessment tool. 1, 2, 3

PHQ-9 score interpretation: 2, 3, 6

• 1-7: Minimal symptoms

• 8-14: Moderate symptoms

• 15-19: Moderate to severe symptoms

• 20-27: Severe symptoms

• Patients with PHQ-9 scores ≥15 require referral to psychiatry or psychology 2, 3, 6

• Pay special attention to item 9 of the PHQ-9, which assesses thoughts of self-harm and requires immediate intervention if present 6

Alternative validated instruments: 1, 3

• Hamilton Depression Rating Scale (HAM-D) 1
• Montgomery-Åsberg Depression Rating Scale (MADRS) 1
• Beck Depression Inventory-II (BDI-II): scores ≥20 suggest clinical depression 1, 3
• Center for Epidemiological Studies–Depression Scale (CES-D): scores ≥16 suggest moderate to severe symptoms 1, 3

Conduct Direct Clinical Interview

Standardized instruments should not replace direct interview by a clinician. 1

• Interview both the patient and family/caregivers to gather collateral information 1
• Adolescents with depression may not clearly identify depressed mood; look for irritability, fatigue, insomnia, weight changes, decline in academic functioning, and family conflict 1
• Obtain information from other sources (e.g., teachers) when appropriate 1

Assess Functional Impairment and Comorbidities

Assessment must include evaluation of functional impairment in different domains and screening for comorbid psychiatric conditions. 1, 3

• Evaluate impairment in school, home, and peer settings 1
• Assess subjective distress 1
• Screen for comorbid conditions including anxiety disorders, substance use disorders, bipolar disorder, and other psychiatric illnesses 1, 3
• Use GAD-7 to assess anxiety symptoms: scores of 5,10, and 15 indicate mild, moderate, and severe anxiety respectively 1, 3

Identify Risk Factors and Stressors

Assess for risk factors that increase likelihood of depression: 1

• Previous personal or family history of depression, bipolar disorder, suicide-related behaviors, substance use, or other psychiatric illness 1
• Significant psychosocial stressors such as family crises, physical/sexual abuse, neglect, trauma history 1
• Frequent somatic complaints 1
• Foster care or adoption status 1

Common Pitfalls to Avoid

• Do not rely solely on screening tools for diagnosis: A positive screen does not equal a diagnosis of major depressive disorder, especially in low-risk populations where positive predictive value may be low 1
• Do not miss medical causes: Failing to rule out medical or substance-induced causes can lead to inappropriate treatment and missed serious conditions 2, 3
• Do not underestimate severity: A PHQ-9 score of 15 represents significant clinical depression requiring professional intervention, not just mild symptoms 6
• Beware of structured interview limitations: Standardized diagnostic interviews may catch unspecific syndromes rather than make specific differential diagnoses, particularly with somatic comorbidity 7
• Do not skip safety assessment: Always assess for suicidal ideation and risk of harm, which requires immediate intervention 1, 3, 6

Special Population Considerations

• Older adults: Depression is more difficult to detect and often presents atypically; use tailored assessment approaches 2
• Patients with cognitive impairment: Modified assessment approaches are necessary 2
• Culturally diverse patients: Use culturally sensitive assessment tools when possible 2