Study: 2 in 5 Drivers Who Use Cannabis & Alcohol Have Driven Under the Influence

A new study from researchers at Columbia University Mailman School of Public Health found that two in five drivers who reported using alcohol and cannabis in the past year drove under the influence of alcohol, cannabis, or both. The study included a sample of 34,514 individuals, including drivers 16-and-older who reported any past-year alcohol and cannabis use in the National Survey on Drug Use and Health from 2016 to 2019.

Priscila Dib Gonçalves, the study’s first author from the Department of Epidemiology at Columbia Mailman School, noted that “alcohol and cannabis are two of the most common substances involved in impaired driving and motor vehicle crashes in the U.S.”

The substances are also the most commonly used drugs in the U.S.

“Examining the effect of simultaneous alcohol and cannabis use on self-report driving under the influence of alcohol-only, cannabis-only, and both substances using a nationally representative sample could contribute to better understanding the impact in adolescents and adults.” – Gonçalves in a press release

From 2016 to 2019, 42 percent of drivers with past-year alcohol and cannabis use reported any past-year DUI, with 8% reporting driving under the influence of only alcohol, 20% reporting driving under the influence of only cannabis, and 14% reporting driving under the influence of both alcohol and cannabis. The study found that simultaneous use was associated with 2.88 times higher odds of driving under the influence of cannabis, and 3.51 times higher odds of driving under the influence of both alcohol and cannabis. Daily use of alcohol and cannabis increases the odds of driving under the influence.

“Our study is unique in that it reports more recent nationally representative data (2016-2019) and compares different types of DUI categories,” Gonçalves said in a statement. “From a harm reduction perspective, identifying which population subgroups are at high risk for DUIs could assist the development of more focused prevention strategies. Future research should also investigate the potential impact of low or ‘promotional’ cannabis prices with higher levels of use, intoxication, and simultaneous use of other substances.”

The study was funded by the National Institute on Drug Abuse and National Center for Injury Prevention and was published in the American Journal of Preventive Medicine.