A 38-year-old woman presents to the psychiatry outpatient clinic with a 4-month history of persistent low mood, anhedonia, and significant weight loss (8 kg). She reports waking up at 4 AM every morning and being unable to return to sleep. She denies suicidal ideation but expresses hopelessness about her future. Her husband reports she has become withdrawn and neglects household responsibilities. On mental status examination, she appears psychomotor retarded with restricted affect. She has no past psychiatric history and denies substance use. What is the most likely diagnosis based on DSM-5 criteria?

Explanation

## Diagnostic Reasoning **Key Point:** This patient meets DSM-5 criteria for Major Depressive Disorder (MDD) based on the presence of ≥5 symptoms during a 2-week period (or longer), representing a change from baseline functioning. ### Symptom Inventory The patient demonstrates: 1. Depressed mood (persistent low mood × 4 months) 2. Anhedonia (loss of interest/pleasure) 3. Weight loss (8 kg, significant) 4. Early morning awakening (4 AM) — a form of sleep disturbance 5. Psychomotor retardation (observable on exam) 6. Social withdrawal and functional impairment 7. Hopelessness (cognitive symptom) **High-Yield:** The presence of **early morning awakening** (terminal insomnia) and **psychomotor retardation** are hallmark features of melancholic depression, a specifier within MDD. ### Severity Assessment Severity is rated as **severe** because: - Marked functional impairment (neglecting household duties, social withdrawal) - Multiple neurovegetative symptoms (sleep, appetite, psychomotor changes) - Duration >2 weeks (actually 4 months, indicating chronic course) - No psychotic features are mentioned, so "without psychotic features" applies **Clinical Pearl:** The 4-month duration and the presence of melancholic features (early morning awakening, psychomotor retardation, anhedonia) distinguish this from adjustment disorder (which requires an identifiable stressor and shorter duration) and from dysthymia (which is chronic but typically milder). ### Why Not Bipolar II? No history of hypomanic episodes, elevated mood, or decreased need for sleep is documented. Bipolar II requires at least one hypomanic episode in addition to depressive episodes.