Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional
Official Title: Effects of Combined Alcohol and Cannabis on Young Drivers' Simulated Driving
Brief 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 residual or 'hangover' effects of these substances on road safety are also not well understood, but may be substantial. To date, the residual effects of combined use have not been examined. The current study will examine the acute and residual 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 25 years will each complete 8 experimental sessions (2 sessions/week). During the first session of each week, subjects 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. Twenty-four hours after alcohol/drug exposure, subjects will attend the second session of the week where driving-related, cognitive, psychomoto