Descriptive Epidemiology of Generalized Anxiety Disorder in Canada

Objective: The first national survey to assess the prevalence of generalized anxiety disorder (GAD) in Canada was the 2012 Canadian Community Health Survey: Mental Health and Well-Being (CCHS-MH). The World Mental Health Composite International Diagnostic Interview (WMH-CIDI), used within the representative sample of the CCHS-MH, provides the best available description of the epidemiology of this condition in Canada. This study uses the CCHS-MH data to describe the epidemiology of GAD.

Method: The analysis estimated proportions and odds ratios and used logistic regression modelling. All results entailed appropriate sampling weights and bootstrap variance estimation procedures.

Results: The lifetime prevalence of GAD is 8.7% (95% CI, 8.2% to 9.3%), and the 12-month prevalence is 2.6% (95% CI, 2.3% to 2.8%). GAD is significantly associated with being female (OR 1.6; 95% CI, 1.3 to 2.1); being middle-aged (age 35-54 years) (OR 1.6; 95% CI, 1.0 to 2.7); being single, widowed, or divorced (OR 1.9; 95% CI, 1.4 to 2.6); being unemployed (OR 1.9; 95% CI, 1.5 to 2.5); having a low household income (<$30 000) (OR 3.2; 95% CI, 2.3 to 4.5); and being born in Canada (OR 2.0; 95% CI, 1.4 to 2.8).

Conclusions: The prevalence of GAD was slightly higher than international estimates, with similar associated demographic variables. As expected, GAD was highly comorbid with other psychiatric conditions but also with indicators of pain, stress, stigma, and health care utilization. Independent of comorbid conditions, GAD showed a significant degree of impact on both the individual and society. Our results show that GAD is a common mental disorder within Canada, and it deserves significant attention in health care planning and programs.