BackgroundPeople from Black ethnic groups (African-Caribbean and Black African) are more prone to develop psychosis in Western countries. This excess might be explained by perceptions of disadvantage.AimsTo investigate whether the higher incidence of psychosis in Black people is mediated by perceptions of disadvantage.MethodA population-based incidence and case-control study of first-episode psychosis (Aetiology and Ethnicity in Schizophrenia and Other Psychoses (ÆSOP)). A total of 482 participants answered questions about perceived disadvantage.ResultsBlack ethnic groups had a higher incidence of psychosis (OR=4.7, 95% CI 3.1–7.2). After controlling for religious affiliation, social class and unemployment, the association of ethnicity with psychosis was attenuated (OR=3.0, 95% CI 1.6–5.4) by perceptions of disadvantage. Participants in the Black non-psychosis group often attributed their disadvantage to racism, whereas Black people in the psychosis group attributed it to their own situation.ConclusionsPerceived disadvantage is partly associated with the excess of psychosis among Black people living in the UK. This may have implications for primary prevention.