Does cannabis exacerbate the effect of alcohol on the risk of crashing? A close look at the best epidemiological evidence
Keywords: Statistical, Epidemiology and Other Road Safety Research Methods, Driver Risk, Drug Driving, Policy Development and Implementation
ACRS
Submission Date: 2019
Abstract
Does the co-use of cannabis exacerbate the effect of alcohol on the risk of crashing? A literature search identified eleven epidemiological studies of the effect of cannabis on the risk of crashing, where the recent use of cannabis was indicated by the detection of THC in oral fluid or blood. Ten of the studies also investigated interactions between cannabis and alcohol, but only one claimed to have found an exacerbation effect. That study was of questionable validity. The review concludes that there is no good epidemiological evidence for an exacerbation effect.