Combined Alcohol and Cannabis Effects on Skills of Young Drivers

Summary

Alcohol and cannabis are the two most widely used substances of abuse in the world and are the psychoactive substances most often found in seriously and fatally injured drivers. In a recent study, it was observed that individuals who reported both driving under the influence of alcohol (DUIA) and the influence of cannabis (DUIC) experienced collision risk that was nearly 4 times that of individuals who reported driving after using only one of these drugs. Recent research in the United States and Canada indicates that the prevalence of DUIC among young drivers of high school and university age, and young adults is similar to, or higher than, the prevalence of DUIA. This is a serious public health issue, since motor vehicle collisions are the leading cause of death in this age group. Given the frequency with which alcohol and cannabis are consumed together, it is important to understand their combined effects on driver behaviour. The current study will examine the acute effects of a moderate dose of cannabis (12.5% THC) combined with an intoxicating amount of alcohol (BAC=0.08) on driving simulator performance of young drivers. Following an eligibility screening and practice session, a total of 70 participants aged 19 to 29 years will each complete 4 experimental sessions. During each session, participants will drink alcohol or placebo alcohol and smoke an active or placebo cannabis cigarette. The effects of alcohol and cannabis on the performance of driving-related skills will be assessed using a high-fidelity driving simulator. Cognitive, psychomotor, and mood effects will also be assessed.

Timeline

Start

2017-07-04

Primary completion

2020-01-17

Completion

2020-01-17

Publications

• Background Lenne MG, Dietze PM, Triggs TJ, Walmsley S, Murphy B, Redman JR. The effects of cannabis and alcohol on simulated arterial driving: Influences of driving experience and task demand. Accid Anal Prev. 2010 May;42(3):859-66. doi: 10.1016/j.aap.2009.04.021.
• Background Downey LA, King R, Papafotiou K, Swann P, Ogden E, Boorman M, Stough C. The effects of cannabis and alcohol on simulated driving: Influences of dose and experience. Accid Anal Prev. 2013 Jan;50:879-86. doi: 10.1016/j.aap.2012.07.016. Epub 2012 Aug 4.
• Di Ciano P, Brands B, Fares A, Wright M, Stoduto G, Byrne P, McGrath M, Hasan OSM, Le Foll B, Wickens CM. The Utility of THC Cutoff Levels in Blood and Saliva for Detection of Impaired Driving. Cannabis Cannabinoid Res. 2023 Jun;8(3):408-413. doi: 10.1089/can.2022.0187. Epub 2023 Feb 2.

Drugs

Indications

No indication recorded.