Psychiatry / Behavioral Science

At least 5 of 9 SIG-E-CAPS symptoms for ≥2 weeks, with at least one being depressed mood or anhedonia; symptoms cause distress/impairment and are not due to another condition.

Sleep changes, Interest loss (anhedonia), Guilt/worthlessness, Energy loss, Concentration difficulty, Appetite change, Psychomotor agitation/retardation, Suicidality — plus depressed mood.

SSRIs (e.g., sertraline, escitalopram) or SNRIs, combined with psychotherapy; first-line because of favorable safety/tolerability over TCAs and MAOIs.

Typically 4-6 weeks at an adequate dose; partial response may warrant dose increase, and full benefit can take up to 8-12 weeks.

PHQ-9 — a 9-item self-report questionnaire scoring each DSM symptom 0-3; also tracks treatment response and screens suicidality (item 9).

Treatment-refractory depression, severe depression with psychotic features, catatonia, acute suicidality requiring rapid response, or when medications are contraindicated (e.g., pregnancy); ECT is among the most effective treatments.