Major Depressive Disorder (Deep Depression): Symptoms, Diagnosis, and Treatment

Major Depressive Disorder (MDD), often called clinical or deep depression, is a serious mental illness characterized by pervasive low mood and functional impairment lasting ≥2 weeks.

Diagnostic Criteria (DSM-5) – ≥5 Symptoms Including 1 or 2:

1. Depressed mood most of the day, nearly every day.
2. Markedly diminished interest/pleasure (anhedonia).
3. Significant weight loss/gain or appetite change.
4. Insomnia or hypersomnia.
5. Psychomotor agitation or retardation.
6. Fatigue/loss of energy.
7. Feelings of worthlessness or excessive guilt.
8. Diminished concentration, indecisiveness.
9. Recurrent thoughts of death, suicidal ideation, or attempt.

Severity and Course

• Mild, moderate, severe (with/without psychotic features).
• Single episode or recurrent.
• Partial remission vs. full remission.

Treatment

• Psychotherapy: CBT, IPT, behavioral activation – first-line for mild-moderate.
• Antidepressants: SSRIs, SNRIs, others – first-line for moderate-severe; combined with therapy for best outcomes.
• Advanced: ECT (severe, treatment-resistant), TMS, ketamine/esketamine, VNS.
• Lifestyle: Exercise, sleep hygiene, social connection, alcohol avoidance.

Critical

Suicidal ideation requires immediate evaluation. Call 988 (US Suicide & Crisis Lifeline) or emergency services. Depression is treatable; most people recover with appropriate care.