JAN 15, 2020 9:26 AM PST

Smoking Weed Before 16 Impairs Driving Ability Even When not High

WRITTEN BY: Annie Lennon

A new study has shown that people who start smoking cannabis on a frequent basis before the age of 16 tend to be worse drivers later in life than those who abstain from the drug- even when they’re not high. 

To conduct the research, researchers at McLean Hospital in Belmont recruited 45 healthy participants to complete a 4.2 mile virtual course using a driving simulator. Of those in the cohort, 17 did not smoke marijuana while 14 consumed the drug heavily from before the age of 16, and 14 started smoking later in life. The virtual course included stop signs, traffic lights, yields, merges, pedestrians and other vehicles. Each participant was graded on their ability to follow traffic rules, stay in their own lanes and their responses to sudden obstacles and potential dangers. 

For the study, those defined as “heavy” smokers had consumed cannabis for five out of the previous seven days prior the simulator, were said to have smoked at least 1,500 times, and tested positive for cannabinoids on biological tests. Prior driving with the simulator, all users had to abstain from the drug for at least 12 hours. 

In their results, the researchers found that those who began smoking cannabis before the age of 16 tended to be poorer drivers than those who started later, or who simply abstained from the  drug altogether. However, when the researchers controlled for self-reported impulsivity among the participants, they found that differences between the groups in driving performance was less significant, suggesting that impulsivity alone among those in the heavy-smoking group may have accounted for much of the variance in simulator values. 

Although the study found something of a correlation between marijuana usage and driving ability, Staci Gruber, one of the study’s leaders, warned against taking her results as evidence against mariuana usage. Given the small sample size of her study, alongside surmounting evidence demonstrating its utility in improving cognitive abilities when used for medicinal purposes, she said, “This doesn’t mean if you put heavy cannabis users on the road they’re going to mow people down and drive horribly — it doesn’t mean they’d hit impaired levels of driving in the real world...It just means there are differences.”


Sources: Boston Globe, 9News and Science Direct

About the Author
  • Science writer with a keen interest in behavioral biology, consciousness medicine and technology. Her current focus is how the interplay of these fields can create meaningful interactions, products and environments.
You May Also Like
MAR 18, 2021
Cannabis Sciences
Migraine Sufferers Who Use Cannabis Have More Headaches
MAR 18, 2021
Migraine Sufferers Who Use Cannabis Have More Headaches
Researchers from Stanford University School of Medicine have found that people who use cannabis for pain relief from chr ...
APR 12, 2021
Cannabis Sciences
How Long Does a Cannabis High Last?
APR 12, 2021
How Long Does a Cannabis High Last?
How long a cannabis high lasts can be very subjective. It is, however, an important matter when considering drug-driving ...
MAY 04, 2021
Health & Medicine
Detecting Driving Impairment From Cannabis Use Is Extremely Tricky, Experts Say
MAY 04, 2021
Detecting Driving Impairment From Cannabis Use Is Extremely Tricky, Experts Say
Don’t drive high is a sensible message, but ultimately nobody really knows the impact of cannabis on an individual ...
MAY 12, 2021
Health & Medicine
Medical Cannabis Increases Quality of Life By Over 50 Percent: UK Study
MAY 12, 2021
Medical Cannabis Increases Quality of Life By Over 50 Percent: UK Study
Real world data from a British study involving over  900 medical cannabis patients has found high quality evidence ...
MAY 19, 2021
Cannabis Sciences
Cannabis May Reduce Pain in Treatment-Resistant Fibromyalgia
MAY 19, 2021
Cannabis May Reduce Pain in Treatment-Resistant Fibromyalgia
An Italian researcher found that long-term use of various cannabis products, including herbal cannabis and oil extracts, ...
JUN 08, 2021
Cannabis Sciences
Can Smoking Weed Help You Lose Weight?
JUN 08, 2021
Can Smoking Weed Help You Lose Weight?
While cannabis is known to increase appetite in what is known as the ‘munchies’, some say they are able to l ...
Loading Comments...