Incidence of Schizophrenia among second-generation immigrants in the Jerusalem perinatal cohort

Objective: Increased incidence of schizophrenia is observed among some immigrant groups in Europe, with the offspring of immigrants, ie "second-generation" immigrants particularly vulnerable. Few contemporary studies have evaluated the risk of schizophrenia among second-generation immigrants in other parts of the world. Methods: We studied the incidence of schizophrenia in relation to parental immigrant status in a population-based cohort of 88829 offspring born in Jerusalem in 1964-1976. Parental countries of birth were obtained from birth certificates and grouped together as (1) Israel, (2) Other West Asia, (3) North Africa, and (4) Europe and industrialized countries. Cox proportional hazards methods were used in adjusting for sex, parents' ages, maternal education, social class, and birth order. Results: Linkage with Israel's Psychiatric Registry identified 637 people admitted to psychiatric care facilities with schizophrenia-related diagnoses, before 1998. Incidence of schizophrenia was not increased among second-generation immigrants in this birth cohort, neither overall nor by specific group. Conclusions: The difference in risk of schizophrenia among second-generation immigrants in Europe and in this Israeli birth cohort suggests that the nature of the immigration experience may be relevant to risk, including reasons for migration, the nature of entry, and subsequent position in the host country for immigrants and their offspring. Minority status may be of importance as, in later studies, immigrants to Israel from Ethiopia had increased risk of schizophrenia.