By Keri Ferguson
While young people may be aware of the dangers of drinking and driving, a recent study by a Western PhD student shows there's work to be done to educate them on the risks of driving under the influence of cannabis (DUIC).
Despite growing evidence that DUIC increases the risk of collisions, the Canadian Centre on Substance Use and Addiction reports youth ages 15 to 24 are more than twice as likely to drive under the influence of cannabis than older Canadians. Yet little is known about the determinants driving this behaviour.
Robert Colonna, BHSc,'17, MSc,'19, a second year PhD student in health promotion, is working to change that, studying the factors causing youth to drive high to help inform effective prevention and intervention efforts.
Colonna began studying the area while starting his master's degree in 2017, one year before Canada legalized recreational marijuana. His early work laid the foundation for his current PhD research and a nationally funded study.
As a member of occupational therapy professor Liliana Alvarez's i-Mobile Driving Research Lab, Colonna first became interested in cannabis use and road safety by observing the culture around him and knowing people who drove impaired.
"It had me wondering why people use cannabis and drive," Colonna said. "With it becoming legalized in 2018, it was the perfect opportunity to explore the reasons and the risks."
First of its kind
Phase one of Colonna's master's research involved designing the Youth Cannabis and Driving Survey, which was recently published in the Journal of Safety Research, a joint publication of the U.S. National Safety Council. Colonna's survey was the first its kind, focusing specifically on Ontario youth drivers (aged 18-24) and cannabis.
"Most surveys focus on alcohol and drug use among the general population, without a focus on cannabis-impaired driving, but this survey was unique and designed with analysis in mind, and really crafted specifically toward youth driving high and the factors predicting that behaviour," Colonna said.
Colonna recruited participants through Facebook, Twitter and LinkedIn, and with help from large organizations such as arrive alive DRIVE SOBER, Ontario Public Health Association, Parachute Canada and Young Drivers of Canada.
Phase two of the project involved focus groups, where youth spoke candidly about cannabis use, legalization, and driving under the influence of cannabis.
Determinants of driving high
Colonna found past cannabis use and DUIC incidence, perceptions on those convicted that actually receive the penalty, moral awareness, perceived danger, minor accident risk, and vicarious punishment avoidance all to be determinants in driving high.
"If people have driven under the influence of cannabis in the past, they are at a greater risk of doing so in the future," Colonna said. "Those who perceive they wouldn't receive penalties and those who think it's not wrong to drive high are at a greater risk of doing it, and youth who think there's a low risk of getting in an accident show a greater chance of driving high in the future."
Sobering results
Colonna's sample showed 70 per cent of the respondents used cannabis in the past year, and 48 per cent of those users reported previously driving under the influence of cannabis. Research coming out of the U.S. shows similar results.
However, Colonna was most struck by the fact that, "youth were really unaware of the risks of driving high - both legally and in terms of collisions and the danger it poses to themselves or others."
"One of the most memorable quotes from the focus groups was when we go out to the bar, usually the designated driver is the one who smokes, while everyone else drinks."
Going national
Colonna said responses from the survey and focus groups help illustrate the need for more research and preventative efforts to reduce the number of current cannabis users driving high, and prevent new cannabis users from driving high in the future.
His study laid the foundation to attract a Canadian Institute Health Research (CIHR) grant to fund a nationwide survey and interviews, targeting provinces where there's higher risk for cannabis-impaired driving.
"That will provide us with a lot more data to build effective preventative efforts," Colonna said.
As part of his PhD candidacy exam, Colonna is currently doing a rapid review of different interventions used in the past to identify characteristics that might have importance in driving high interventions. He is also conducting a Delphi study, where experts in impaired driving are ranking those characteristics and identifying which ones to develop as an intervention strategy. Young cannabis users are being asked to do the same, to see how their opinions contrast with those of the experts and build mobile technology interventions based on that.
The potential implications and applications are exciting for Colonna, who is most interested in prevention, harm reduction and public safety.
"We need to educate people and use better messaging to promote safe cannabis use. I think studies like these are going to help inform those efforts."
