Meta-analytic reviews suggest that international migrants have a two to threefold increased risk of psychosis compared with the host population, and the level of risk varies by country of origin and host country. This increased risk may persist into the second and third generations. Incidence rates are not typically found to be elevated in the country of origin; therefore it is believed that the migratory or postmigration experience may play a role in the etiology.
The migration-related emergence of psychotics disorders is a potential concern in Canada, which receives 250,000 new immigrates and refugees each year. However, there is a notable lack of current epidemiological information on the incidence of psychosis among these groups.
So begins a new paper that seeks to answer a basic question: are there certain migrant groups more at risk of psychotic disorders in Canada?
This week’s Reading: “Incidence of psychotic disorders among first-generation immigrants and refugees in Ontario” by Kelly K. Anderson et al., which was published in the CMAJ in June.
Of course, studying the incidence of psychotic disorders in immigrant populations isn’t exactly novel – there is a rich literature in this field. And the Canadian angle isn’t novel either – as the paper points out, previous studies have considered B.C. hospital admission rates for schizophrenia in European migrants in the early 1900s.
But this paper aims to consider recent data and Canadian data – relevant in a country that takes in 250,000 migrants a year. The paper focuses on Ontario, where first generation migrants constitute almost a third of the population.