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).
[1] 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.
The National Comorbidity Survey: Reinterview (NCS-2) was a follow-up study conducted between 2001 and 2002.
The participants in NCS-1 were re-interviewed with the aim to collect information about changes in mental disorders, substance use disorders, and the predictors and consequences of these changes over the ten years between the two surveys.
The National Comorbidity Survey Replication (NCS-R) was a study done with 9,282 new participants.