29. Does Psychosis Risk Vary by Age-At-Migration and Region of Origin? A National Cohort Study of 1.8 Million People
Year: 2017
Type: article
Study design: Observational Study
Abstract: Background: Research has found that schizophrenia rates are increased among first- and second-generation migrants. However, there are still inconsistent findings for bipolar disorder. We sought to determine whether these risks varied in a national Swedish population cohort and whether rates varied by age at migration and region of origin. Methods: Swedish population registers were used to ascertain diagnosis of schizophrenia, schizoaffective disorder, bipolar with psychosis, and bipolar without psychosis, migration status, and covariates (n = 1 796 257). We used Cox regression analysis to test whether migrant status, age at migration (infancy, early childhood, middle childhood, adolescence, and early adulthood), and region of origin affected psychosis risk. Results: Age- and sex-adjusted hazard ratios were elevated in first- and second-generation migrants for all psychotic disorders, compared with native Swedes. Schizophrenia risk was elevated at all ages of migration (Infancy HR 1.6, 95% CI 1.0–2.4; Early childhood HR 2.8, 95% CI 2.0–3.8; Middle childhood HR 2.7, 95% CI 2.2–3.3; Adolescence HR 3.0, 95% CI 2.2–4.0; Early adulthood HR 4.3, 95% CI 2.4–7.6). For bipolar disorder without psychosis, there was no increased risk among second-generation migrants (HR 1.0 95% CI 1.0–1.1), while first-generation migrants had lower risk than Swedish-born (HR 0.7, 95% CI 0.6–0.8). The only age group of increased risk was those who migrated during infancy (HR 1.2, 95% CI 1.0–1.5). There was variation in risk by region of origin for all disorders; African migrants had significantly elevated schizophrenia risk compared with all other migrants (HR 5.3, 95% CI 4.0–6.9). For bipolar without psychosis, Finnish migrants (HR 1.9, 95% CI 1.3–2.9) and North American migrants had the highest incidence rates (HR 1.9, 95% CI 1.3–2.8). Conclusion: Different patterns of risk by age at migration suggest that the experience of adverse social environments may be important at different developmental stages for schizophrenia compared with bipolar disorder. Further, the detrimental effect of migration may be specific to psychotic disorders, given the weaker patterns of risk between migration and non-psychotic bipolar disorder. Differing patterns of risk by region of origin may indicate that the pre-and post-migration psychosocial stressors, treatment-seeking behavior, or diagnostic patterns may vary between migrant groups, but further research is required to determine the underlying mechanism driving this variation.
Source: Schizophrenia Bulletin
Institution: University College London
Language: English
Topic: Migration, Health and Trauma
Subfield: Clinical Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W2599212509