National Comorbidity Survey

The National Comorbidity Survey: Baseline (NCS-1) was the first large-scale field survey of mental health in the United States. Conducted from 1990–1992, disorders were assessed based on the diagnostic criteria of the then-most current DSM manual, the DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised). The study has had large-scale implications on mental health research in the United States, as no widespread data on the prevalence of mental illness was previously available.