Searching for the causes of schizophrenia: the role of migrant studies.

There have been consistent reports in the literature of increased rates of hospital admissions for schizophrenia among Afro-Caribbean (West Indian) migrants to England. Recent evidence for even higher rates in the British-born second generation is reviewed, together with the methodological limitations of such studies. It is concluded that there is probably an epidemic of schizophrenia and related psychoses in this group of migrants although further prospective and longitudinal studies are required. The findings point to the potentially important role of migrant studies in determining environmental risk factors for schizophrenia.