Epidemiology of geriatric affective disorders.

Recent Epidemiologic Catchment area studies found the prevalence of major depression to be only about 1% in community-dwelling elders; other less severe depressive disorders, however, may be present in over 25% of this population. Furthermore, at least 8000 persons over age 60 commit suicide each year, making up nearly one quarter of the total number reported, a rate much higher than expected given the proportion of elderly in the US population. Bipolar disorder, on the other hand, is much less common than unipolar depression at a rate of about 0.1% in the community; in nursing homes, however, as many as 10% of residents may have this condition. Sociodemographic correlates of depression in late life include female sex, divorced or separated marital status, low income or educational level, inadequate social support, and recent negative and unexpected life events. In particular, physical health has a major impact on mood and well-being; consequently, rates of major depressive disorder in elders hospitalized with medical illness are over 10 times that reported in the community.