title: Elaboration on the association between immigration and schizophrenia: a population-based national study disaggregating annual trends, country of origin and sex over 15 years.
abstract: OBJECTIVE
  Generally, immigrant status and male sex are separately documented to increase the risk of schizophrenia; although population-based risk trends by sex and immigration over time have not been examined. This study aims to examine the extent to which immigration acts as a risk factor for schizophrenia, delineated by origin, sex and year, using national population-based data over 15 years.
  
  
  METHODS
  Data on all first psychiatric admissions from 1978 to 1992 (n = 10,892) from the National Psychiatric Hospitalization Case Registry of the State of Israel were merged with aggregate national data from the Israeli Central Bureau of Statistics.
  
  
  RESULTS
  Compared to native-born Israelis, people who migrated prior to the age of 15 (n = 2,335) were at a greater risk of schizophrenia (n = 8,557; RR = 1.6, 95% CI = 1.53; 1.68), particularly those from Far Eastern (RR = 2.43, 95% CI = 1.91; 3.1) and Caribbean and South American (RR = 1.94, 95% CI = 1.51; 2.51) countries. Aggregate risk was higher among female than male immigrants and over the 15-year study immigration-related risk declined across the sexes.
  
  
  CONCLUSIONS
  The current findings replicate past research showing that immigrants, particularly from a social minority, as suggested by the social defeat-hypothesis, are at an increased risk of schizophrenia, and extend past findings to show that risk at least in Israel has decreased with time irrespective of sex.
authors.affiliation: Bar Ilan University, Ramat Gan, Israel.
authors.forename: Nomi
authors.initials: N
authors.lastname: Werbeloff
authors.forename: Stephen Z
authors.initials: SZ
authors.lastname: Levine
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rabinowitz
mesh_terms: D000293:Adolescent; D000328:Adult; D004641:Emigration and Immigration / Q000639:trends*; D005260:Female; D006801:Humans; D007557:Israel / Q000208:ethnology; D008297:Male; D012042:Registries; D012307:Risk Factors; D012559:Schizophrenia / Q000208:ethnology*; D012737:Sex Factors; D013997:Time Factors; D014171:Transients and Migrants / Q000145:classification / Q000523:psychology*; D055815:Young Adult