Some recreational marijuana users are dangerous drivers, even when they aren’t high. That’s according to a brand new study done by Harvard researchers and published this week in the scientific journal Drug and Alcohol Dependence.
The study, Recreational Cannabis Use Impairs Driving Performance in the Absence of Acute Intoxication, found that chronic, heavy, recreational cannabis users who started smoking pot before the age of 16 performed worse on driving tests compared to non-users.
When placed in a driving simulator, sober cannabis users who started using the drug in their teens had more accidents, drove at higher speeds and blew through more red lights, compared to people who had never used marijuana.
The theory here is that early marijuana use changes the brain, leaving affected people more impulsive and more apt to make rash decisions.
“This research suggests that early exposure to cannabis may result in difficulties performing complex cognitive tasks,” said co-author Staci Gruber, an associate professor of psychiatry and director of Marijuana Investigations for Neuroscientific Discovery at Harvard Medical School and McLean Hospital.