Frontiers in Psychiatry (May 2021)

Cannabis Use and Car Crashes: A Review

  • Ulrich W. Preuss,
  • Ulrich W. Preuss,
  • Marilyn A. Huestis,
  • Miriam Schneider,
  • Derik Hermann,
  • Beat Lutz,
  • Alkomiet Hasan,
  • Joseph Kambeitz,
  • Jessica W. M. Wong,
  • Eva Hoch

DOI
https://doi.org/10.3389/fpsyt.2021.643315
Journal volume & issue
Vol. 12

Abstract

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In this review, state-of-the-art evidence on the relationship between cannabis use, traffic crash risks, and driving safety were analyzed. Systematic reviews, meta-analyses, and other relevant papers published within the last decade were systematically searched and synthesized. Findings show that meta-analyses and culpability studies consistently indicate a slightly but significantly increased risk of crashes after acute cannabis use. These risks vary across included study type, crash severity, and method of substance application and measurement. Some studies show a significant correlation between high THC blood concentrations and car crash risk. Most studies do not support this relationship at lower THC concentrations. However, no scientifically supported clear cut-off concentration can be derived from these results. Further research is needed to determine dose-response effects on driving skills combined with measures of neuropsychological functioning related to driving skills and crash risk.

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