OBJECTIVES To compare the rates of schizophrenia among 1st and 2nd generation immigrants from two distinct backgrounds and across sequential periods of immigration. METHODS A 30-years retrospective cohort study (187,184 individuals) of 1st and 2nd generation East-African immigrants (EAIs) and former Soviet-Union immigrants (FSUIs) who migrated to Israel between 1980 and 2012. EAIs were further divided according to waves of immigration. Period prevalence was calculated between the years 2002-2012. Multivariate logistic regression models were used to examine the association between immigration-related factors and prevalence of schizophrenia (Native-Born Israelis serving as reference group). RESULTS The prevalence of schizophrenia in 1st generation EAIs and FSUIs was 1.8% and 1.2%, respectively, compared to 1.0% among NBIs (p<0.001). The prevalence of schizophrenia among 2nd generation EAIs and FSUIs was 1.3% and 0.8%, respectively, compared to 0.6% among NBIs (p<0.001). Adjusted odds ratios for developing schizophrenia compared to NBIs were 1.6 (95%CI:1.4-1.8) and 2.1 (95%CI:1.6-2.7), among 1st and 2nd generation EAIs and 1.1 (95%CI:0.9-1.2) and 1.3 (95%CI:1.0-1.8) among 1st and 2nd generation FSUIs respectively. Among EAIs, we observed the highest rate of schizophrenia in the pioneer wave of immigrants with gradual decline across subsequent waves: 2.4%, 1.9% and 1.0% for the 1st, 2nd and 3rd waves of immigration, respectively (p<0.001). CONCLUSIONS The increased risk for developing schizophrenia among 2nd generation immigrants and among pioneer groups of immigrants emphasizes the importance of persistent investment in acculturation. Further studies elucidating the impact of country of origin and ethnic density on the risk for developing schizophrenia are warranted.

中文翻译：

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原籍国和移民潮对第一代和第二代移民精神分裂症患病率的影响：一项为期 30 年的回顾性研究

目的 比较来自两个不同背景和连续移民时期的第一代和第二代移民的精神分裂症发病率。方法 对 1980 年至 2012 年间移居以色列的第一代和第二代东非移民 (EAI) 和前苏联移民 (FSUI) 进行 30 年回顾性队列研究（187,184 人）。移民。期间流行率是在 2002-2012 年间计算的。多变量逻辑回归模型用于检查移民相关因素与精神分裂症患病率之间的关联（作为参考组的以色列人）。结果 第一代 EAI 和 FSUI 中精神分裂症的患病率分别为 1.8% 和 1.2%，而 NBI 中为 1.0%（p<0.001）。第二代 EAI 和 FSUI 中精神分裂症的患病率分别为 1.3% 和 0.8%，而 NBI 中为 0.6%（p<0.001）。与 NBI 相比，发生精神分裂症的调整优势比分别为 1.6 (95%CI:1.4-1.8) 和 2.1 (95%CI:1.6-2.7)，在第一代和第二代 EAI 和 1.1 (95%CI:0.9-1.2) 和第 1 代和第 2 代 FSUI 分别为 1.3 (95%CI:1.0-1.8)。在 EAI 中，我们观察到第一波移民中精神分裂症的发病率最高，随后的浪潮逐渐下降：第一、第二和第三波移民分别为 2.4%、1.9% 和 1.0%（p<0.001）。结论 第二代移民和移民先驱群体患精神分裂症的风险增加，强调了持续投资于文化适应的重要性。