What topics does this cannabis study cover?

This study covers research on: Mental Health.

Where was this research published?

Published in Advances in therapy on May 23, 2026.

Untreated ADHD poses greater driving risk than cannabis use

The Impact of Untreated Attention-Deficit/Hyperactivity Disorder on Motor Vehicle Accidents: A Systematic Review and Meta-Analysis.

Advances in therapy • May 23, 2026 • Moderately Relevant

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AI Summary

This meta-analysis examined the relationship between untreated ADHD and motor vehicle accidents (MVAs), comparing it to other well-known driving risk factors including cannabis use. The study found that drivers with untreated ADHD had a 93% increased risk of accidents compared to the general driving population. When analyzed alongside other impairment factors, cannabis (THC) use increased accident risk by 85%, making it a significant but somewhat less dangerous impairment factor than untreated ADHD. For perspective, the study also found that sleepiness/fatigue posed a 162% increase in accident risk, while opioids and benzodiazepines increased risk by 53%.

The research highlights an important but underappreciated public health concern: untreated ADHD poses comparable or greater driving dangers than cannabis use, alcohol, and excessive speed. While cannabis impairment is frequently discussed in traffic safety contexts, untreated ADHD remains less recognized despite its substantial impact on driving safety. The authors emphasize that treating ADHD can significantly reduce accident risk, suggesting that proper medical management may be more effective than relying solely on behavioral modifications or restrictions for this population.

For cannabis users and researchers, this study provides important context: while THC use does increase driving accident risk substantially, it ranks below fatigue and at similar levels to some prescription medications. This comparison doesn't minimize cannabis impairment concerns but rather illustrates that multiple factors—including untreated neurological conditions—deserve equal attention in road safety initiatives and policy discussions.

📄 Original Abstract

This meta-analysis quantified the dangers of driving with untreated ADHD and compares consequences for untreated drivers with ADHD to those of better publicized accident risk factors. A systematic literature review and meta-analysis of published data was performed to determine the correlation between driving with untreated ADHD and motor vehicle accidents (MVAs). Separate analyses were performed for alcohol use and driving, excessive speed, cannabis use, sleepiness/fatigue, opioids/benzodiazepines, and cell phone use. Four studies showed significantly higher odds of an accident among untreated ADHD drivers versus the general population of drivers-a 93% increase [(significant pooled odds ratio (OR), 95% confidence interval (CI) for the overall effect, p < 0.001]. The odds of having an accident was increased by 85% in THC/cannabis users (significant pooled OR, 95% CI, p < 0.001); 162% increase in sleepy/tired drivers (significant pooled effect OR, 95% CI, p = 0.004); and 53% increase in opioid or benzodiazepine users (significant pooled OR, 95% CI, p < 0.001). This analysis found that MVAs occur significantly more frequently with drivers with untreated ADHD compared to the general population of drivers. Increasing awareness of accident risk among drivers with untreated ADHD and the positive impact of treating ADHD on driving highlights the importance of treating ADHD.