Increasing prevalence of schizophrenia in Canada

The burden of schizophrenia for Canadian society is significant. In a review of incidence and prevalence studies published in peer-reviewed journals dating from 1953 through 2006, Dealberto estimated the one-year prevalence of schizophrenia in Canada at 2.5 to 5.6 per 1000. The investigator found that published incidence and prevalence rates have increased during the past 4 decades. Furthermore, the prevalence and incidence in Canada were greater than international median rates, with Canada’s estimated incidence rate situated between the 45th and 100th percentiles of international comparators.

Dealberto explained the relatively high prevalence of schizophrenia in Canada by three possible factors. First, many studies have found that immigrants have an increased incidence of schizophrenia in both the first and second generations. Canada has a high rate of immigration, about twice that of the United States; 20% of Canadians were born in another country. Second, schizophrenia is more common in countries at high latitude, although the cause of this effect is unknown. Third, urban populations have a greater prevalence of schizophrenia, and 80% of Canadians live in cities.

Population-based studies of the prevalence of treatment-resistant schizophrenia in Canada do not exist. Most reports indicate that treatment resistance occurs in about 30% of patients, hence based on Dealberto’s findings, the estimated one-year prevalence of treatment-resistant schizophrenia in Canada is 7.5 to 17 per 10,000.

Given these data, and assuming a continuation of current immigration policy in Canada, governments at federal and provincial levels must plan for and fund the health-care and social-service needs of a growing number of people with this disorder.

Reference

Dealberto MJ. Are the rates of schizophrenia unusually high in Canada? A comparison of Canadian and international data. Psychiatry Res. 2013;209(3):259-265. Abstract

One thought on “Increasing prevalence of schizophrenia in Canada

  1. Three factors which may be at play:
    1. Use of marijuana by teens, ( pre- 20 years of age), in Canada.
    2. Possible connection between low Vitamin D levels in people living in northern latitudes and schizophrenia, (especially in darker complected individuals).
    3. Stress of immigration.

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