OBJECTIVE: The authors examined the course of depression over 2 years for outpatients with and without a history of hypertension, a history of myocardial infarction, or current insulin-dependent diabetes. METHOD: Among outpatient visitors to the practices of 523 general medical clinicians and mental health specialists, 626 depressed patients were followed for 1 or 2 years with a telephone-administered interview based on the format of the National Institute of Mental Health Diagnostic Interview Schedule. RESULTS: Depressed patients with and without medical illness had high rates of persistent depressive symptoms and spells over 2 years. Patients with a lifetime history of myocardial infarction had significantly more spells of depression over the first follow-up year, more total symptoms of depression in the second follow-up year, and more depressive symptoms at the end of each follow-up year than depressed patients without myocardial infarction. The course of depression did not differ significantly for depressed patients with and without a lifetime history of hypertension or current insulin-dependent diabetes. CONCLUSIONS: Among depressed adult outpatients, a history of myocardial infarction is associated with a particularly poor clinical prognosis. A relatively high percentage of all depressed patients in this study had persistent depression regardless of the extent of medical comorbidity.Abstract Teaser