A woman is evaluated 6 weeks after delivery for persistent depressed mood, anhedonia, insomnia, and feelings of worthlessness. The most likely diagnosis is:

• A. Postpartum blues
• B. Major depressive disorder
• C. Adjustment disorder
• D. Bipolar disorder

Answer: (B)

Persistent depressive symptoms emerging after delivery are most consistent with major depressive disorder. Birth can trigger mood disturbances, but postpartum blues are confined to the first couple of weeks and resolve quickly. Six weeks after delivery, ongoing depressed mood with anhedonia, insomnia, and feelings of worthlessness meets the pattern and duration of a major depressive episode, which includes persistent depressed mood and anhedonia plus at least a couple of other symptoms causing distress or impairment. Bipolar disorder would require manic or hypomanic features, which aren’t described here. An adjustment disorder would be tied to a specific stressor and not meet full depressive criteria. So the presentation aligns with major depressive disorder occurring in the postpartum period.