Attention-Deficit/Hyperactivity Disorder and Alcohol and Other Substance Use Disorders in Young Adulthood: Findings from a Canadian Nationally Representative Survey.

AIM: (a) To document the prevalence and odds of (i) alcohol use disorders, (ii) cannabis use disorders, (iii) other drug use disorders and (iv) any substance use disorder (SUD), among young adults with and without ADHD, and (b) to investigate the degree to which the association between ADHD and SUDs is attenuated by socio-demographics, early adversities and mental health.

METHOD: Secondary analysis of the nationally representative Canadian Community Health Survey-Mental Health (CCHS-MH). The sample included 6872 respondents aged 20-39, of whom 270 had ADHD. The survey response rate was 68.9%.

MEASUREMENTS: Substance Use Disorder: World Health Organization's Composite International Diagnostic Interview criteria, SUDs, were derived from lifetime algorithms for alcohol, cannabis and other substance abuse or dependence. ADHD was based on self-report of a health professional's diagnosis.

FINDINGS: One in three young adults with ADHD had a lifetime alcohol use disorder (36%) compared to 19% of those without ADHD (P < 0.001). After adjusting for all control variables, those with ADHD had higher odds of developing alcohol use disorders (OR = 1.38, 95% CI: 1.05, 1.81), cannabis use disorders (OR = 1.46, 95% CI: 1.06, 2.00), other drug use disorders (OR = 2.07, 95% CI: 1.46, 2.95) and any SUD (OR = 1.69, 95% CI: 1.28, 2.23). History of depression and anxiety led to the largest attenuation of the ADHD-SUD relationship, followed by childhood adversities and socioeconomic status.

CONCLUSIONS

Young adults with ADHD have a high prevalence of alcohol and other SUDs. Targeted outreach and interventions for this extremely vulnerable population are warranted.