Cannabis replaces alcohol as the most common harmful substance: driver survey

“However, given the very high crash risk associated with alcohol, and the fact that most ‘cannabis-positive’ drivers had low levels of THC (the active substance in cannabis), it can be concluded that driving after drinking remains a greater problem in Canada. ”

The study also found that Atlantic Canada led the country in the share of injured drivers who had used marijuana more often.

Of the 624 injured drivers from Nova Scotia, New Brunswick and Newfoundland and Labrador tested during the study period, 26 percent of drivers tested positive for cannabis, while 22 percent tested positive for alcohol. A total of 70 percent tested positive for drugs or alcohol, which was also higher than the national average.

Lead author Dr. Jeff Brubacher, from the University of British Columbia’s department of emergency medicine, said the overall prevalence of impaired driving in Atlantic Canada was something that struck him.

“That was the most striking thing,” he said. “I would say it’s a problem across the country, but it seems to be worse in Atlantic Canada.”

Researchers in British Columbia have been studying cannabis in blood alcohol since 2012 and it’s clear the number of drivers with pot in their system has increased since legalization in 2018, he said.

“I would still say good, old-fashioned alcohol is probably still the biggest single substance problem,” Brubacher said. “But a new problem is the combination of alcohol and cannabis, and that is a bad combination.”

The research shows that cannabis intoxication causes attention deficits, slows reaction time and impairs tasks such as following ability – such as staying within a lane – or checking the speedometer. However, it is said that regular cannabis users may develop tolerance to some of its effects.

“The effect of alcohol on driving and road safety is well studied and understood,” the study says. “Unlike alcohol, it is often not possible to predict how driving behavior will be affected by different drug-blood-alcohol concentrations.”

According to Brubacher, the target group for this study includes emergency room physicians, public health officials, police and organizations that help spread awareness about safe driving.

“It’s just to warn people about the risks of driving under the influence, about the risks of mixing alcohol and cannabis,” he said. “I really hope that we can continue to collect this kind of data, and I hope that … police can use it to guide enforcement, and that injury prevention folks can use it for public education.”

This report by The Canadian Press was first published June 24, 2024.

Hina Alam, The Canadian Press