ADHD and autistic traits were each linked to substance use in different ways | Research

The takeaway

Both ADHD symptoms and autistic traits were associated with cannabis use disorders, but autistic traits showed a paradoxical pattern: less likely to drink alcohol, but more likely to develop alcohol dependence once drinking started.

Read this if you have ADHD or autism spectrum traits and want to understand your relationship with substance use risk.

Both ADHD and autistic traits independently predicted substance use disorders

What the researchers found

In a study of 3,080 young adult Australian twins, researchers examined how ADHD symptoms and autistic traits independently related to substance use. Greater ADHD symptoms and higher autistic traits scores were each associated with elevated rates of regular smoking, cannabis use, and nicotine, alcohol, and cannabis use disorders, even after controlling for conduct disorder.

A paradoxical pattern emerged for autistic traits and alcohol: individuals with higher autistic traits were less likely to report drinking to intoxication (possibly due to social factors, since drinking is often a social activity), but when they did drink, they were at elevated risk for developing alcohol dependence.

The findings suggest that both ADHD and autistic traits represent independent vulnerability factors for substance use disorders, operating through different mechanisms.

Why it matters

ADHD and autism spectrum traits frequently co-occur, and each independently increases substance use vulnerability. Understanding these separate pathways helps identify at-risk individuals and tailor prevention approaches.

The numbers in context

3,080 twins (mean age 31.9 years). Both ADHD symptoms and autistic traits independently associated with cannabis use disorders. Autistic traits associated with less alcohol use but more alcohol dependence once use began.

How the study worked

Cross-sectional analysis of interview and questionnaire data from 3,080 young adult Australian twins (mean age 31.9 years). DSM-IV substance use disorders were assessed. Logistic regression controlled for conduct disorder, sex, age, and zygosity.

What this study cannot tell us

Twin sample may not represent the general population. Self-report measures of autistic traits and ADHD symptoms are dimensional and not equivalent to clinical diagnoses. Cross-sectional design cannot establish causation.

How to read the evidence

Well-powered twin study with appropriate controls, though cross-sectional design limits causal interpretation.

When this study was published

Published in 2014.

The bigger picture

The finding that autistic traits create vulnerability to dependence despite lower rates of substance initiation suggests that the social protection against starting substance use does not extend to protection against addiction once use begins. This has implications for substance use screening in autism spectrum populations.

Questions still open

What mechanisms explain the vulnerability to dependence despite lower initiation rates in people with autistic traits? Would early screening and intervention for substance use in neurodivergent populations reduce disorder rates? Do ADHD and autistic traits interact synergistically to increase risk?

Common questions

Does ADHD increase cannabis use risk?

In this study, greater ADHD symptoms were associated with higher rates of cannabis use and cannabis use disorders, even after controlling for conduct disorder.

Are people with autistic traits at risk for substance problems?

Yes, but in a complex way. People with higher autistic traits were less likely to drink alcohol (possibly because drinking is often social) but were more likely to develop alcohol dependence once they started. They also showed elevated cannabis use disorder rates.

Read the original research

ADHD symptoms, autistic traits, and substance use and misuse in adult Australian twins.

Journal of studies on alcohol and drugs, 75(2), 211-21

View on PubMed ↗

Citation

De Alwis, Duneesha; Agrawal, Arpana; Reiersen, Angela M; Constantino, John N; Henders, Anjali; Martin, Nicholas G; Lynskey, Michael T. (2014). ADHD symptoms, autistic traits, and substance use and misuse in adult Australian twins.. Journal of studies on alcohol and drugs, 75(2), 211-21.