The prevalence of depression among nursing home residents was estimated by screening a group of residents selected from a random sample on the basis of cognitive status; it ranged from 18–20% for major depression to 27–44% for other dysphoric states. Though individual patients were observed to change over a 6-month period, depression as assessed with the Geriatric Depression Scale was, in general, persistent. Major depression was clinically confirmed in 8 of 10 patients identified at screening. It was characterized by medical disorders that complicated diagnosis and treatment, and by increased mortality relative to the rest of the population.