The epidemiology of psychosis: The Suffolk County Mental Health Project

This article describes the rationale, aims, and methodology of an epide-mlological study of psychosis being conducted in Suffolk County, New York. A sample of first-admission patients is drawn from 10 inparJent and 25 outpatient facilities. Diagnos-tic psychosodal interviews are con-ducted shortly after admission to treatment, and at 6- and 24-month followup. Consensus diagnoses are made after each interview. Demo-graphic and clinical background characteristics of the first 250 sub-jects enrolled over a 2-year period are presented here. The response rate was 76 percent. Based on the initial interview, 75 percent of subjects re-ceived a diagnosis involving psycho-sis. The three most common diag-noses were schizophrenia, bipolar disorder with psychotic features, and major depression with psychotic fea-tures. Among subjects with psycho-sis, 58 percent of males and 29 per-cent of females had a history of substance abuse/dependence. Gender differences were found on several background and clinical characteris-tics. Males were somewhat younger, less likely to have ever married, and had less education. Although the me-dian length of hospitallzation was the same for females and males (27 days), females were more likely to be hospitalized within 1 month of the occurrence of their first psychotic symptom (60 % of females compared to 37 % of males). Subjects with schizophrenia-related disorders were significantly more impaired on an assessment of negative symptoms than were affectively ill subjects, but clinical ratings of depression were not significantly different across di-agnostic groups. In May 1989 we initiated an epidemi-ological study of psychotic disorders, focusing on first-admission patients with psychotic symptoms admitted to psychiatric treatment facilities i