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Study breakdown

Young adults with ADHD had significantly higher rates of cannabis and other substance use disorders

Cross SectionalModerate evidence
The takeaway

In a nationally representative Canadian survey, young adults with ADHD had 46% higher odds of cannabis use disorder, with one in three having a lifetime alcohol use disorder compared to one in five without ADHD.

People with ADHD, mental health clinicians, and addiction researchers.

36% of young adults with ADHD had lifetime alcohol use disorder vs 19% without

What the researchers found

After adjusting for sociodemographics, childhood adversities, and mental health, young adults with ADHD had higher odds of alcohol use disorders (OR 1.38), cannabis use disorders (OR 1.46), other drug use disorders (OR 2.07), and any substance use disorder (OR 1.69). Depression and anxiety history explained the largest portion of the ADHD-substance use disorder relationship.

Why it matters

Understanding that ADHD significantly increases substance use disorder risk, particularly through depression and anxiety pathways, can help target prevention efforts.

The numbers in context

6,872 respondents aged 20-39. 270 with ADHD. Alcohol use disorder: 36% of ADHD vs 19% without. Cannabis use disorder OR 1.46. Other drug use disorder OR 2.07. Depression and anxiety were the strongest mediators.

How the study worked

Secondary analysis of the nationally representative Canadian Community Health Survey-Mental Health (6,872 respondents aged 20-39, including 270 with ADHD). Substance use disorders diagnosed using WHO CIDI criteria. ADHD based on self-reported professional diagnosis.

What this study cannot tell us

Cross-sectional design cannot establish temporal order. ADHD based on self-reported diagnosis, not standardized assessment. Canadian population may not generalize to other countries.

How to read the evidence

Nationally representative survey with validated diagnostic criteria, though cross-sectional design limits causal inference.

When this study was published

Published in 2022.

The bigger picture

The finding that depression and anxiety mediate much of the ADHD-substance use relationship suggests that treating psychiatric comorbidities in ADHD may help prevent substance use disorders.

Questions still open

  • Would treating depression and anxiety in ADHD patients reduce their substance use disorder risk? Are specific ADHD subtypes more vulnerable to cannabis use disorder?

Common questions

Why are people with ADHD more vulnerable to substance use disorders?
The study found that depression and anxiety history explained the largest portion of the increased risk, followed by childhood adversities and socioeconomic status, suggesting these co-occurring conditions drive much of the vulnerability.
How much higher was the cannabis use disorder risk?
Young adults with ADHD had 46% higher odds of developing a cannabis use disorder (OR 1.46) after adjusting for multiple factors including demographics, childhood adversity, and mental health.

Read the original research

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

Alcohol and alcoholism (Oxford, Oxfordshire), 57(3), 385-395

Citation

Fuller-Thomson, Esme; Lewis, Danielle A; Agbeyaka, Senyo. (2022). Attention-Deficit/Hyperactivity Disorder and Alcohol and Other Substance Use Disorders in Young Adulthood: Findings from a Canadian Nationally Representative Survey.. Alcohol and alcoholism (Oxford, Oxfordshire), 57(3), 385-395. https://doi.org/10.1093/alcalc/agab048

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