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Refugee status increases risk for psychotic disorders among Ontario immigrants

Among immigrants residing in Ontario, refugee status was a significant predictor of schizophrenia or schizoaffective disorders and immigrants from the Caribbean and Bermuda had the highest incidence rates, according to study results.

“Meta-analytic reviews suggest that international migrants have a two- to threefold increased risk of psychosis compared with the host population,” study researcher Kelly K. Anderson, PhD, of the University of Western Ontario, and colleagues wrote. “The migration-related emergence of psychotic disorders is a potential concern in Canada, which receives about 250,000 new immigrants and refugees each year.”

Kelly K. Anderson

To determine incidence of schizophrenia and schizoaffective disorders among immigrants, researchers reviewed medical records for 4,284,694 individuals, aged 14 to 40 years, living in Ontario since April 1999.

Overall, 9.8% of study participants were first-generation migrants and 22.7% of migrants had refugee status.

Among the general population, the incidence rate for psychotic disorders was 55.6 per 100,000 person-years (95% CI, 54.9-56.4). Immigrants had a similar incidence rate, at 51.7 per 100,000 person-years (95% CI, 49.2-54.4).

Prevalence of psychotic disorders was higher among refugees, who had an incidence rate of 72.8 per 100,000 person-years (95% CI, 67.1-78.9).

Refugee status was an independent predictor of increased risk for psychotic disorders (IRR = 1.27; 95% CI, 1.04-1.56).

Immigrants from the Caribbean and Bermuda had a higher risk for psychotic disorders (IRR = 1.6; 95% CI, 1.29-1.98) compared with the general population. Immigrants from northern Europe (IRR = 0.5; 95% CI, 0.28-0.91), southern Europe (IRR = 0.6; 95% CI, 0.41-0.9) and East Asia (IRR = 0.56; 95% CI, 0.41-0.78) had lower risks vs. the general population.

Among immigrants with refugee status, individuals from East Africa (IRR = 1.95; 95% CI, 1.44-2.65) and South Asia (IRR = 1.51; 95% CI, 1.08-2.12) had significantly higher risk for psychotic disorders compared with the general population.

“Our findings suggest that particular immigrant and refugee groups may have a higher risk of psychotic disorders,” Anderson and colleagues wrote. “Given that Canada is currently experiencing a rapid growth in the population of foreign-born citizens — one of the highest rates of any Western nation — the mental health status of immigrants and refugees should be a national priority.”

Further, the study findings may highlight a need for more frequently updated data on incidence of psychotic disorders among all population groups in Canada, according to James B. Kirkbride, PhD, of the University College London, and Anna-Clara Hollander, PhD, of the Karolinska Institute in Sweden.

“The linked study highlights the essential need to provide routine data of sufficient quality and detail for the precise estimation of incidence and prevalence of psychotic disorders among all subgroups of the general population,” they wrote in an accompanying editorial. “It is only on the foundation of robust epidemiologic estimates of incidence of psychiatric distress that the vital care provided through clinical services and public mental health policy can be optimized.” – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.