The NIMH Epidemiologic Catchment Area program. Historical context, major objectives, and study population characteristics.

The National Institute of Mental Health multisite Epidemiologic Catchment Area (ECA) program is described in the context of four previous psychiatric epidemiologic surveys that included a combined total of 4,000 subjects from Stirling County, the Baltimore Morbidity Study, Midtown Manhattan, and the New Haven third-wave survey. The ECA program is distinguished by its sample size of at least 3,500 subjects per site (about 20,000 total); the focus on Diagnostic Interview Schedule--defined DSM-III mental disorders; the one-year reinterview-based longitudinal design to obtain incidence and service use data; the linkage of epidemiologic and health service use data; and the replication of design and method in multiple sites. Demographic characteristics of community and sample populations are provided for New Haven, Conn, Baltimore, and St Louis.