Canada legalized recreational cannabis more than two years ago, but the passage of time has not translated into the anticipated lower use among young people, notes an evaluation of study data involving 100,000-plus youths.

“High prevalence of youth cannabis use in this sample remains a concern,” notes the pre-proof study recently published online in Preventive Medicine Reports, an open access companion journal to Preventive Medicine. “These data suggest that the Cannabis Act has not yet led to the reduction in youth cannabis use envisioned in its public health approach,” write authors from Ontario and Quebec

Trying to characterize overall use trends among youth pre- and post-legalization, investigators reviewed data about secondary students at 76 schools in Alberta, B.C., Ontario and Quebec from the COMPASS study. Using cross-sectional and longitudinal approaches, weed use was considered at two school years before legalization (in 2016-2017 and 2017-2018) and at one point after (in 2018-2019

“Youth cannabis use remains common with ever-use increasing from 30.5 per cent in 2016-2017 to 32.4 per cent in 2018-2019,” the study notes.

Ever-use was defined as any previous cannabis use, current use was at least once a month or more frequently, regular use was at least once a week or more frequently, and occasional use was one to three times monthly or less often.

While the odds of weed use in a repeat cross-sectional sample youths was 1.05 times those of the preceding year, the longitudinal sample indicated “no significant differences in trends of cannabis use over time.”

Study authors further note that higher ever-use “does not appear to have translated to a change in regular use.”

With regard to differences by province, the repeat cross-sectional model shows “students in Quebec and B.C. were significantly less likely to report regular use than students in Alberta. In the longitudinal model, Alberta students also had significantly higher odds than Ontario students of reporting regular use.”

“Youth cannabis use remains common with ever-use increasing from 30.5 per cent in 2016-2017 to 32.4 per cent in 2018-2019.” / PHOTO BY GETTY IMAGES

One factor may be that Alberta has more retail stores than other jurisdictions in the country, the study points out. “Taken in combination with differing approaches to cannabis distribution and age restrictions, as well as less tangible factors such as public health efforts, it is likely that provincial differences in youth cannabis use will persist and potentially become more pronounced over time,” it notes.

Just how legalization has influenced youth use of weed is decidedly mixed. “Though many investigations have detected few harmful consequences, others found that youth were adversely affected,” study authors write.

A U.S. study published in 2015 notes, “We find increases in the probability of current marijuana use, regular marijuana use and marijuana abuse/dependence among those aged 21 or above.” Compare that to another U.S. study published three years later, in which investigators reported that enacting medical marijuana laws “is associated with decreases in marijuana and other drugs in early adolescence in those states.”

Figures from the Government of Canada, citing Health Canada’s Canadian Tobacco, Alcohol and Drugs Survey, notes that in 2017, 15 per cent of Canadians 15 and older had used cannabis in the past 12 months. Broken down by age, 19 per cent of those aged 15 to 19 had used weed, 33 per cent of people between 20 and 24 years had used cannabis and 13 per cent of respondents 25 and older had done so.

More recently, an analysis from the Canadian Institute for Health Information confirmed what many have reported for some time: COVID-19 has ratcheted up cannabis and alcohol use. For respondents 18 to 24, 36 per cent had used weed.

One potential stumbling block seems to be that “policy approaches in most of these contexts have tended to be market-driven rather than informed by principles of public health.” / PHOTO BY ALEXLMX / ISTOCK / GETTY IMAGES PLUS

Investigators in the recent COMPASS data review note that one of the key drivers of legalizing recreational cannabis was to reduce use among youth, with the legislation’s primary emphasis being on public health and education.

“The adverse effects of cannabis use on developing brains and the fact that adult substance use trajectories are most often rooted in adolescence were likewise identified as factors to consider during the legalization process,” study authors write.

One potential stumbling block in jurisdictions where adult-use cannabis is now allowed seems to be that “policy approaches in most of these contexts have tended to be market-driven rather than informed by principles of public health.”

That being the case, it seems not to have positively shaped youth weed use in Canada and legalization has not resulted in “the slowing or reversing of concerning trends in youth cannabis use.”

Future approaches must “not only characterize youth cannabis use overall, but also investigate how it is affected by individual, community and provincial factors, including prevention and harm reduction programs, as recreational cannabis use becomes embedded in Canadian society,” authors recommend.