Epidemiological studies have established that the use of cannabis can increase the risk of a motor vehicle collision. A number of variables can influence the effects of cannabis on driving. For example, frequent users of cannabis have been shown to have different cognitive and physiological responses to cannabis as compared to occasional users. In addition, we know that younger drivers are more likely to be involved in motor vehicle collisions after alcohol use as compared to older users. The contribution of age and experience with cannabis on cannabis-mediated effects on driving have yet to be delineated in laboratory studies. The purpose of the present investigation will be to determine whether cannabis has different effects on driving in young, as compared to middle aged, drivers. Half of each age group will be occasional users of cannabis and the other half will be frequent users.~Eligible participants will attend the laboratory for two test sessions; in one session they will smoke a cannabis cigarette and in the other they smoke a placebo cigarette. Participants will drive a driving simulator before and after smoking the cigarette. Blood for measurement of THC and metabolites will also be collected before smoking the cigarette and at a number of times after smoking. Subjective and cognitive tasks will be completed before and after smoking.~It is hoped that the findings of this study will help to inform public perception and policy into the potential effects of cannabis on driving.
Epidemiological studies suggest that the use of cannabis is associated with an increase in the risk of motor vehicle collisions. It is also known that younger users may be at increased risk for motor vehicle collisions. Further, the frequency with which cannabis is used may be an important variable in determining the effects of cannabis on driving. The purpose of the present study will be to investigate the effects of cannabis on simulated driving in young as compared to middle-aged drivers. Half of the participants will be occasional users of cannabis and half will be frequent users of cannabis.