Conduct disorder and attention-deficit/hyperactivity disorder as risk factors for prescription opioid use

Existing studies of attention deficit/hyperactivity disorder (ADHD), conduct disorder (CD), and substance use or substance use disorders have produced mixed results, with some identifying a direct link between ADHD and general or disordered substance use and others suggesting that comorbid CD may explain this relationship. Insufficient research has addressed the issue, which is particularly relevant in the context of the opioid crisis. This study examined the association of probable ADHD and childhood CD with self-reported opioid use in a general-population sample.

The 2011-2013 cycles of the CAMH Monitor, a cross-sectional survey of adults (18+ years) from Ontario, Canada provided data from 6074 respondents. Binary logistic regressions were conducted of self-reported medical, non-medical, and any prescription opioid use in the previous 12 months, assessing demographic characteristics, perceived physical and mental health, and probable ADHD, childhood (before age 15 years) symptoms of CD, or their combination.

Adjusting for potential covariates, probable ADHD alone was not associated with prescription opioid use. Childhood symptoms of CD significantly predicted non-medical use (OR = 2.10, 95% CI = 1.10, 4.03). ADHD and CD symptoms combined significantly predicted medical (OR = 3.27, 95% CI = 1.20, 8.91), non-medical (OR = 4.73, 95% CI = 1.05, 21.30), and any (OR = 3.02, 95% CI = 1.13, 8.11) prescription opioid use, although a low base rate of non-medical use may have negatively affected model fit.

Previous findings relating ADHD to opioid use could be explained, in part, by the high rate of comorbidity between ADHD and CD. These data support prevention and treatment programs targeting individuals with comorbid ADHD and CD symptoms.