Dr. Bhopal interviews Dr. Amit Chopra, a psychiatrist and sleep specialist at Massachusetts General Hospital and Harvard Medical School, about the bidirectional relationship between major depressive disorder and sleep disorders. Dr. Chopra explains that persistent insomnia increases future depression risk (about twofold overall and nearly fourfold in adolescents), and DSM-5 now treats insomnia as an independent disorder rather than “secondary.” They discuss other common comorbid sleep conditions in depression (obstructive sleep apnea, restless legs syndrome, circadian rhythm disorders, hypersomnolence), consequences of missed diagnoses (recurrence, partial response, treatment resistance), shared neurobiology, and insomnia as an independent suicidality risk factor. The episode outlines a practical 10–15 minute sleep assessment, when to order sleep studies, and evidence-based treatments including CBT-I (techniques, delivery formats, digital options) and selective medication use when needed.