Migration and schizophrenia: an examination of five hypotheses

Summary

Data are presented on rates of admission for schizophrenia for the native born and the four largest foreign born populations living in England in 1981 (Irish, Indian, Pakistani and Caribbean born). These data show that, in general, the foreign born have higher rates of admission for schizophrenia, and a higher proportion of all diagnoses accounted for by this disorder than do the native born. The exception is Pakistani born women who have conspicuously low rates. Five hypotheses are examined to account for these differences. The apparently high rates of schizophrenia found for the Indian born of both sexes, and Pakistani born men can be accounted for to a large extent by the demographic differences that exist between them and the native born. The Irish born residents of England have rates comparable with the Irish in Ireland who also show much higher rates than do the native English. There is no completely satisfactory account for the very high rates found for Caribbean born men and women but a combination of adverse post migration experiences and tendency to misdiagnose schizophrenia in this group is offered as a tentative explanation for at least some of the excess. The low rates of admission for schizophrenia of Pakistani women is attributed to a tendency on their part to opt out of the formal mental health system after an initial encounter, possibly to return to their native land.