Generalized anxiety disorder among adults with attention deficit hyperactivity disorder

Abstract

Background: Research has identified a link between Attention-Deficit Hyperactivity Disorder (ADHD) and Generalized Anxiety Disorder (GAD). The aims of this study were to investigate the relationship between ADHD and GAD, and to identify significant correlates of GAD among those with ADHD.

Methods: Data were derived from the nationally representative 2012 Canadian Community Health Survey-Mental Health. The sample included 6,989 respondents aged 20-39, of whom 682 had GAD. Bivariate and logistic regression analyses were conducted to determine the degree to which the association between ADHD and GAD was attenuated by demographics, socioeconomic status, social support, spirituality, childhood adversities, depression, and substance abuse/dependence. Additional analyses were conducted using the subsample of those diagnosed with ADHD (n = 272) to determine factors associated with GAD.

Results: 1 in 9 respondents with GAD had ADHD, in comparison to 1 in 33 of those without GAD. The age-sex-race adjusted odds of GAD were four-fold for those with ADHD in comparison to those without ADHD. After adjusting for all covariates, the odds of GAD were still more than double for those with ADHD. Factors associated with GAD among those with ADHD include being female, having an income <$40,000, having fewer close relationships, and having a lifetime history of depression.

Limitations: Cross-sectional design prohibits causal inferences.

Conclusion: The high co-morbidity between ADHD and GAD emphasizes the need for targeted intervention to support these often overlapping disorders.

Keywords: ADHD; Anxiety; Canadian Community Health Survey; GAD; Mental illness.