Study: Marijuana’s Role in Crash Risk Often Overstated

OSLO, NORWAY — Studies estimating the likelihood of THC-positive drivers being involved in motor vehicle accidents compared to drug-free drivers often fail to adequately control for potentially confounding variables, according to a literature review published online ahead of print in the journal Addiction.

Norwegian researchers reviewed more than 20 driving culpability studies, as well as two meta-analyses, published between the years 1982 and 2015. They found that some studies possessed methodological shortcomings that led to authors’…