“Alcohol and cannabis are two of the most common substances involved in impaired driving and motor vehicle crashes” in the United States, said Priscila Dib Gonçalves, the study’s first author, in a news release.
Use of both substances together has led to more severe and fatal driving-related outcomes when compared to how many of these outcomes resulted from the use of either substance alone, especially among younger people, previous research found.
The authors used data from more than 34,000 drivers who answered questions about their drug use and driving habits for the National Survey on Drug Use and Health between 2016 and 2019.
People who simultaneously used cannabis and alcohol were nearly three times more likely to drive under the influence of cannabis, and three and a half times more likely to drive under the influence of both drugs, the authors found.
Of all study participants, 57% to 68% were male, White, had a family income of $40,000 or less, and lived in a state where medical cannabis was legal.
This study shows that most DUI now is not related to alcohol use alone,” said Yvonne Terry-McElrath, a senior research associate at the University of Michigan’s Institute for Social Research, via email.
If you have recently used cannabis or alcohol and are considering traveling, have someone who isn’t intoxicated do the driving, Degutis said.