Major Depressive Disorder (DSM-5): Diagnostic Criteria & Clinical Approach

DSM-5 Criteria for Major Depressive Episode

Five (or more) of the following present during the same 2-week period, representing a change from previous functioning; at least one is (1) depressed mood or (2) anhedonia:

1. Depressed mood most of the day, nearly every day (self-report or observed). Note: In children/adolescents, may be irritable mood.
2. Markedly diminished interest/pleasure in all/almost all activities.
3. Significant weight loss/gain (>5% body weight/month) or appetite decrease/increase.
4. Insomnia or hypersomnia nearly every day.
5. Psychomotor agitation or retardation (observable).
6. Fatigue or loss of energy.
7. Feelings of worthlessness or excessive/inappropriate guilt.
8. Diminished ability to think/concentrate or indecisiveness.
9. Recurrent thoughts of death, suicidal ideation, attempt, or specific plan.

Additional Requirements

• Clinically significant distress/impairment in social, occupational, or other functioning.
• Not attributable to substance/medication, another medical condition, or better explained by schizoaffective, schizophrenia, bipolar, or other psychotic disorder.
• No history of manic/hypomanic episode (unless substance/medical induced).

Specifiers (Clinical Relevance)

• Severity: Mild, Moderate, Severe.
• With anxious distress, mixed features, melancholic features, atypical features, psychotic features, peripartum onset, seasonal pattern.

Diagnostic Process

• Comprehensive psychiatric interview + collateral history.
• Rule out medical mimics (thyroid, B12, folate, electrolytes, cortisol, neuroimaging if indicated).
• Standardized scales (PHQ-9, HAM-D, MADRS) for baseline/tracking.
• Suicide risk assessment at every visit.

Treatment Overview

• Psychotherapy: CBT, IPT, behavioral activation, ACT.
• Pharmacotherapy: SSRIs first-line; SNRIs, bupropion, mirtazapine as alternatives.
• Combination therapy superior for moderate-severe.
• ECT, TMS, ketamine/esketamine for treatment-resistant depression.
• Lifestyle: exercise, sleep hygiene, social rhythm, omega-3.