Incidence of first-contact psychosis in São Paulo, Brazil

BACKGROUND: Little is known about the incidence of first-episode psychosis in urban centres of low- or middle-income countries. AIMS: To estimate the incidence of psychosis in São Paulo, a large metropolis of Brazil. METHOD: Prospective survey of first-episode psychosis among residents aged 18-64 years resident in a defined area of São Paulo, over a 30-month period (July 20 2002-December 2004). Assessments were carried out with the SCID-I, and diagnoses given according to DSM-IV criteria. Population at risk was drawn from the 2000 Census data. RESULTS: There were 367 first-episode cases identified (51% women), and almost 40% fulfilled criteria for schizophrenia or schizophreniform disorder. The incidence rate for any psychosis was 15.8/100 000 person-years at risk (95% CI 14.3-17.6). Incidence of non-affective psychoses was higher among younger males. CONCLUSIONS: Incidence of psychosis in São Paulo was lower than expected for a large metropolis.