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Psychosis more common in refugees than migrants, native-born Swedes

Refugees had an increased risk for psychosis and non-affective psychotic disorders compared with non-refugee migrants and native-born Swedish individuals.

“Immigrants and their descendants are, on average, 2.5 times more likely to have a psychotic disorder than the majority ethnic group in a given setting, although the exact risk varies by ethnicity and setting,” Anna-Clara Hollander, PhD, of Karolinska Institutet, Stockholm, and colleagues wrote. “Possible explanations center on various social determinants of health, including severe or repeated exposure to psychosocial adversities such as trauma, abuse, socioeconomic disadvantage, discrimination, and social isolation.”

To determine if refugees have increased risk for schizophrenia and other non-affective psychotic disorders, researchers analyzed Swedish national register data for 1,347,790 individuals. Study participants included individuals born in Sweden to Swedish parents (88.4%), refugees (1.8%), and non-refugee migrants (9.8%) from the Middle East and north Africa, sub-Saharan Africa, Asia and Eastern Europe and Russia. Participants were followed from age 14 years or arrival in Sweden until diagnosis of a non-affective psychotic disorder, emigration, death or through 2011.

During 8.9 million person years of follow-up, 3,704 cases of non-affective psychotic disorders were identified.

The crude incidence rate of non-affective psychotic disorders was 38.5 per 100,000 person years among Swedish-born participants, 80.4 per 100,000 person years in non-refugee migrants, and 126.4 per 100,000 person years in refugees.

Compared with Swedish-born participants, refugees had an increased risk for psychosis, with an adjusted hazard ratio of 2.9 (95% CI, 2.3-3.6). Migrants had an adjusted hazard ratio of 1.7 (95% CI, 1.3-2.1) for psychosis.

Increased risk for psychosis in refugees compared with migrants was more pronounced among men (P = .001) and was present for refugees from all regions except sub-Saharan Africa.

Rates among refugees and migrants from sub-Saharan Africa were similarly high compared with Swedish-born participants.

“The most obvious implication to be drawn from these findings is that refugees are particularly vulnerable to developing non-affective psychoses and that, as the authors state, there is a ‘need to take the early signs and symptoms of psychosis into account in refugee populations as part of any clinical mental health service response to current global humanitarian crises,’” Cornelius Katona, PhD, medical director of the Helen Bamber Foundation, London, wrote in an accompanying editorial. “As Hollander and colleagues also point out, one of the key limitations of their study is the lack of information on post-migration risk factors such as racism and discrimination. Consideration also needs to be given to the challenges that asylum seekers face during what is often a prolonged and distressing process. The relatively ‘generous’ asylum policies practiced in Sweden may have reduced the effect of these factors in Hollander and colleagues’ study.” – by Amanda Oldt

Disclosure: Hollander reports receiving financial support from FORTE. Please see the full study for a list of all authors’ relevant financial disclosures.