LIFETIME PREVALENCE, DEMOGRAPHIC RISK-FACTORS, AND DIAGNOSTIC VALIDITY OF NONAFFECTIVE PSYCHOSIS AS ASSESSED IN A US COMMUNITY SAMPLE - THENATIONAL COMORBIDITY SURVEY

Background: We seek to estimate lifetime prevalence and demographic co rrelates of nonaffective psychosis in the US population assessed by a computer-analyzed structured interview and a senior clinician. Methods : In the National Comorbidity Survey, a probability subsample of 5877 respondents were administered a screen for psychotic symptoms. Based o n the response to this screening, detailed follow-up interviews were c onducted by mental health professionals (n=454). The initial screen an d clinical reinterview were reviewed by a senior clinician. Results ar e presented for narrowly (schizophrenia or schizophreniform disorder) and broadly (all nonaffective psychoses) defined psychotic illness. Re sults: One or more psychosis screening questions were endorsed by 28.4 % of individuals. By computer algorithm, Lifetime prevalences of narro wly and broadly defined psychotic illness were 1.3% and 2.2%, respecti vely. Of those assigned a narrow diagnosis by the computer, the senior clinician assigned narrow and broad diagnoses to 10% and 37%, respect ively. By clinician diagnosis, lifetime prevalence rates of narrowly a nd broadly defined psychosis were 0.2% and 0.7%, respectively. A clini cian diagnosis of nonaffective psychosis was significantly associated with low income; unemployment, a marital status of single, divorced, o r separated; and urban residence. Clinician confirmation of a computer diagnosis was predicted by hospitalization neuroleptic treatment, dur ation of illness, enduring impairment, and thought disorder. Conclusio ns: Lifetime prevalence estimates of psychosis in community samples ar e strongly influenced by methods of assessment and diagnosis. Although results using computer algorithms were similar in the National Comorb idity Survey and Epidemiologic Catchment Area studies, diagnoses so ob tained agreed poorly with clinical diagnoses. Accurate assessment of p sychotic illness in epidemiologic samples may require collection of ex tensive contextual information for clinician review.