OBJECTIVE: To study the epidemiology of depressive disorder in younger and older medical inpatients. DESIGN, PATIENTS, & SETTING: Depressive disorders were examined using the Diagnostic Interview Schedule in 116 young and 332 elderly medically ill men hospitalized in a VA medical center. RESULTS: Major depressive disorder was diagnosed in 22.4% of men under 40 and 13.3% of those age 70 or over; minor depression was found in 18.1% of young and 29.2% of older men. Besides age, other risk factors for major depression were impaired social support, severe medical illness or functional disability in older men, and history of psychiatric problems primarily in younger men; specific medical diagnosis was not a risk factor. Major depression was associated with more severe symptomatology in younger patients; in both age groups, however, symptoms were of prolonged duration and frequently included suicidal thoughts. CONCLUSIONS: Depressive disorder in hospitalized male veterans is common, varies with age, severity of medical illness, degree of social support, and history of psychiatric problems and is associated with considerable psychological morbidity.