Citation

Brands B, Mann RE, Wickens CM, Sproule B, Stoduto G, Sayer GS, Burston J, Pan JF, Matheson J, Stefan C, George TP, Huestis MA, Rehm J, Le Foll B. Drug Alcohol Depend. 2019; 205: e107641.

Affiliation

Department of Pharmacology and Toxicology, University of Toronto, 27 King's College Circle, Toronto, Ontario, M5S3H7, Canada; Department of Psychiatry, University of Toronto, 250 College Street, Toronto, Ontario, M5T1R8, Canada; Translational Addiction Research Laboratory, Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario, M5S2S1, Canada; Department of Family and Community Medicine, University of Toronto, 500 University Avenue, 5th Floor, Toronto, Ontario, M5G 1V7, Canada; Institute of Medical Sciences, University of Toronto, 1 King's College Circle, Room 2374, Toronto, Ontario, M5S 1A8, Canada.

Copyright

(Copyright © 2019, Elsevier Publishing)

DOI

10.1016/j.drugalcdep.2019.107641

PMID

31678833

Abstract

BACKGROUND: Although driving under the influence of cannabis is increasingly common among young adults, little is known about residual effects on driver behavior. This study examined acute and residual effects of smoked cannabis on simulated driving performance of young cannabis users.

METHODS: In this double-blind, placebo-controlled, parallel-group randomized clinical trial, cannabis users (1-4 days/week) aged 19-25 years were randomized with a 2:1 allocation ratio to receive active (12.5% THC) or placebo (0.009% THC) cannabis in a single 750 mg cigarette. A median split (based on whole-blood THC concentrations at the time of driving) was used to divide the active group into low and high THC groups. Our primary outcome was simulated driving performance, assessed 30 min and 24 and 48 h after smoking. Secondary outcomes included blood THC concentrations, subjective drug effects, and heart rate.

RESULTS: Ninety-six participants were randomized, and 91 were included in the final analysis (30 high THC, 31 low THC, 30 placebo). Mean speed (but not lateral control) significantly differed between groups 30 min after smoking cannabis (p ≤ 0.02); low and high THC groups decreased their speed compared to placebo. Heart rate, VAS drug effect and drug high increased significantly immediately after smoking cannabis and declined steadily after that. There was little evidence of residual effects in any of the measures.

CONCLUSION: Acutely, cannabis caused decreased speed, increased heart rate, and increases in VAS drug effect and drug high. There was no evidence of residual effects on these measures over the two days following cannabis administration.


Keyword: Cannabis impaired driving


Copyright © 2019 Elsevier B.V. All rights reserved.

Language: en

Keywords

Cannabis; Residual effects; Simulated driving; Young adults