(Fredericton) Six-year analysis of more than 10,000 Canadian drivers involved in motor vehicle collisions suggests cannabis has overtaken alcohol as the most common impairing substance detected in post-crash blood tests .
The National Drug Driving Study 2024, conducted by the University of British Columbia, says researchers analyzed blood samples from drivers in British Columbia, Alberta, Saskatchewan, Ontario , Quebec, Nova Scotia, New Brunswick and Newfoundland and Labrador between 2018 and 2023.
They found that 54% of these injured drivers tested positive for at least one impairing substance, and of this group, 16.6% had cannabis in their blood, while 16% had alcohol.
“Driving after consuming cannabis appears to be an emerging problem in Canada and may now be more common than driving after drinking alcohol,” the study says.
“However, given the very high crash risk associated with alcohol and the fact that most cannabis ‘positive’ drivers had low levels of THC [la substance active du cannabis], we can conclude that driving after drinking remains a greater problem in Canada. »
The study also found that Atlantic Canada led the country in the proportion of injured drivers more likely to have used cannabis.
Among the 624 injured drivers from Nova Scotia, New Brunswick and Newfoundland and Labrador who were tested during the study period, 26% of drivers tested positive for cannabis while 22 % tested positive for alcohol. Overall, 70% had used either drugs or alcohol, which is also higher than the national average.
The main author, Dr Jeff Brubacher, who works in the department of emergency medicine at the University of British Columbia, said one important finding was the overall prevalence of impaired driving in Atlantic Canada.
“That’s 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 and blood alcohol since 2012, and it is clear that the number of drivers with marijuana in their system has increased since legalization in 2018, said Dr.r Brubacher.
The study indicates that cannabis intoxication causes attention deficits, slows reaction time and impairs tasks such as tracking ability – like staying in a lane – or monitoring the speedometer. However, Mr. Brubacher specifies that habitual cannabis users can develop a tolerance to some of its effects.