There have been a number of studies pointing to higher rates of schizophrenia and other psychoses in the Black Caribbean population in the U.K. The AESOP (aetiology and ethnicity in schizophrenia and other psychoses) study found rates of schizophrenia and manic psychosis in this group to be nine times greater than in the White British population. There has been a lot of speculation about the reasons for this disparity, most of them centring on the role of socio-economic disadvantage and racial discrimination. A study of 781 people in South-East London and Nottingham compared those experiencing a first episode of psychosis with those from a similar background unaffected by the condition. On all the indicators the people who had developed psychosis were more socially disadvantaged and isolated than healthy people. The more disadvantaged people were the more likely they were to develop psychosis, a pattern which held true for White British and Black Caribbean people. The indicators of social disadvantage and isolation were more common in Black Caribbean participants than White British ones.
Morgan, C. ... [et al] - Cumulative social disadvantage, ethnicity and first-episode psychosis: a case-control study Psychological Medicine December 2008, 38(12), 1701-1715