The incidence of schizophrenia in the African-Caribbean population in England is reported to be raised.
Researchers identified people aged 16-64 years in three well-defined English areas (over a 2-year period in Southeast London and Nottingham and a 9-month period in Bristol). Standardized incidence rates and incidence rate ratios (IRR) for all major psychosis syndromes for all main ethnic groups were calculated.
“We found remarkably high IRRs for both schizophrenia and manic psychosis in both African-Caribbeans (schizophrenia 9?1, manic psychosis 8?0) and Black Africans (schizophrenia 5?8, manic psychosis 6?2) in men and women. IRRs in other ethnic minority groups were modestly increased as were rates for depressive psychosis and other psychoses in all minority groups. These raised rates were evident in all age groups in our study” reported Paul Fearon, Institute of Psychiatry.
Ethnic minority groups are at increased risk for all psychotic illnesses but African-Caribbeans and Black Africans appear to be at especially high risk for both schizophrenia and mania.
These findings suggest that
(a) either additional risk factors are operating in African-Caribbeans and Black Africans or that these factors are particularly prevalent in these groups, and that
(b) such factors increase risk for schizophrenia and mania in these groups.