Many studies have reported an increased incidence of psychiatric disorder (particularly psychotic disorders) among first generation adult immigrants, along with an increasing risk for ethnic minorities living in low-minority concentration neighborhoods. These studies have depended mostly on European case-based databases. In contrast, North American studies have suggested a lower risk for psychiatric disorder in immigrants, although the effect of neighborhood immigrant concentration has not been studied extensively.

Using multi-level modeling to disaggregate individual from area-level influences, this study examines the influence of first generation immigrant status at the individual level, immigrant concentration at the neighborhood-level and their combined effect on 12-month prevalence of mood, anxiety and substance-dependence disorders and lifetime prevalence of psychotic disorder, among Canadians.

Individual-level data came from the Canadian Community Health Survey (CCHS) 1.2, a cross-sectional study of psychiatric disorder among Canadians over the age of 15 years; the sample for analysis was n=35 708. The CCHS data were linked with neighborhood-level data from the Canadian Census 2001 for multi-level logistic regression. Immigrant status was associated with a lower prevalence of psychiatric disorder, with an added protective effect for immigrants living in neighborhoods with higher immigrant concentrations. Immigrant concentration was not associated with elevated prevalence of psychiatric disorder among non-immigrants.

The finding of lower 12-month prevalence of psychiatric disorder in Canadian immigrants, with further lessening as the neighborhood immigrant concentration increases, reflects a model of person–environment fit, highlighting the importance of studying individual risk factors within environmental contexts.