An Examination of Comorbid Generalized Anxiety Disorder and Chronic Pain on Substance Misuse in a Canadian Population-Based Survey.

Objectives: Chronic pain and generalized anxiety disorder (GAD) are co-occurring, and both conditions are independently associated with substance misuse. However, limited research has examined the impact of comorbid GAD and chronic pain on substance misuse. The aim of this article was to examine the associations between comorbid GAD and chronic pain conditions compared to GAD only with nonmedical opioid use, drug abuse/dependence, and alcohol abuse/dependence in a Canadian, population-based sample.
Methods: Data came from the 2012 Canadian Community Health Survey-Mental Health ( N = 25,113). Multiple logistic regressions assessed the associations between comorbid GAD and chronic pain conditions (migraine, back pain, and arthritis) on substance misuse.
Results: Comorbid GAD + back pain and GAD + migraine were associated with increased odds of nonmedical opioid use compared to GAD only. However, the relationship was no longer significant after controlling for additional chronic pain conditions. No significant relationship was found between GAD + chronic pain conditions with drug or alcohol abuse/dependence.
Conclusions: Comorbid GAD + back pain and GAD + migraine have a unique association with nonmedical opioid use in Canadians compared to GAD only, and chronic pain multimorbidity may be driving this relationship. Results emphasize the need for screening for substance misuse and prescription access in the context of GAD and comorbid chronic pain.