This investigation compares the incidence of the major mental disorders among native-born residents of New York State with those who have migrated into New York from other states and from other countries. The authors conclude that the rate of first admissions to hospitals for mental disease was much higher for migrants than for natives, and that the differential in some instances was as high as three hundred percent. This relationship held true for all forms of psychosis, including organic brain disease, as well as all age groups.

The book describes the method and the data on which these conclusions are based. In addition it contains a critical summary of similar investigations conducted elsewhere, and an analysis of the methodological difficulties involved in such studies.

Unfortunately the theoretical implication of these data is far from clear, convincing though the factual conclusions may be. However, as these data may shed some light on epidemiology of mental illness, they are worthy of consideration.