A population-based examination of the co-occurrence and functional correlates of chronic pain and generalized anxiety disorder

Objectives: This study aimed to: 1) Establish the prevalence of co-occurring chronic pain conditions (i.e., arthritis, back pain, and migraines) and generalized anxiety disorder (GAD), and 2) Examine levels of pain severity, disability, and work absenteeism among comorbid chronic pain conditions and GAD. Methods: Data were analyzed from the 2012 Canadian Community Health Survey-Mental Health (CCHS-MH; N = 25,113). Chi-square analyses assessed whether significant differences existed in pain severity in those with comorbid chronic pain and GAD versus pain conditions alone. Multivariable regressions examined the association between comorbid chronic pain and GAD with functional outcomes. Results: The weighted prevalence of GAD among those with chronic migraines, arthritis and back pain was 6.9%, 4.4%, and 6.1% respectively, compared to 2.6% among the entire sample. Severity of pain was increased among those with comorbid chronic pain and GAD compared with chronic pain conditions alone. Migraine was the only pain condition that was significantly associated with disability in our most stringent adjustment model. After controlling for other psychiatric disorders, comorbid GAD and chronic pain was not associated with work absenteeism. Conclusion: Chronic pain is common among the Canadian population and is associated with substantial disability. Results demonstrated that GAD is prevalent among chronic pain conditions, and comorbidity is associated with greater pain severity. GAD in the context of migraines, in particular, may represent an important treatment target to reduce disability.