Many Medical Marijuana Users Drive High, Study Shows

Henrietta Strickland
January 12, 2019

"Using marijuana can result in changes in your reaction time, how well coordinated you are, and we need those functions when we're driving to respond to unexpected events", said Bonar. We know things about how alcohol affects our body.

The study, conducted by the University of Michigan, Iowa State University and VA Center for Clinical Management Research, studied almost 800 patients.

More than half also said they drove while they were a little high and over 20-percent reported they were "Very high" when they were behind the wheel.

That's a concern for law enforcement.

The lead author, Erin E. Bonar, Ph.D., assistant professor of psychiatry and a practicing clinical psychologist at U-M Addiction Treatment Services, said she finds the results of the survey of 790 MI medical marijuana users troubling. Right now, there is no reliable roadside test to know for sure if a driver is impaired by cannabis.

The researchers recruited 790 of the state's medical marijuana patients who were seeking medical marijuana certification for chronic pain in 2014 and 2015 and asked them to report on their driving habits from the past six months.

The study was funded by the National Institutes of Health, including the National Institute on Drug Abuse.

"We have 33 states where essentially politicians have voted that this should be a legal medical therapy and we don't have data from rigorous scientific studies to define what the safety is", he said.

Bonar said mixing marijuana and driving is risky. That includes being able to tell patients how long to wait before driving and figuring out ways to reliably know what role it may be playing in motor vehicle accidents.

Other reports by Click Lancashire

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