Rise in cannabis use among Canadian youth preceded legalization

National discussions on cannabis legalization, along with increased access to medical marijuana, may have encouraged more high school students to consume the drug years before it became legal in Canada.

A recent study using data from more than 230,000 questionnaires by Canadian high school students in grades 9 to 12 found that almost 10 per cent reported having used the drug at least once per week in 2017-18, with a further 18 per cent saying they had used it at least once in the last year.

Both weekly and occasional use reached their lowest points in 2014-15 (9 percent and 15 percent respectively) and have since been rising steadily.

"The problem was developing while legalization was being discussed, but well before concrete steps to change the law were taken," said lead author Alex Zuckermann, a post-doctoral fellow with the Public Health Agency of Canada working in the School of Public Health and Health Systems.

"With medicinal use more widespread and talk of total legalization starting, we saw a shift in public perception starting around 2014. Before that, youth cannabis use was declining. These changing social norms may have contributed to rising youth use."

The work used data from the COMPASS Study, an annual survey of high school students in grades 9 to 12 in Ontario and Alberta. The demographic groups that saw the biggest increases since 2014-15 were female and Indigenous youth. Weekly use for females went from 7 to 8 percent, and occasional use from 17 to 19 percent during this time period. Indigenous youth weekly use went from 23 to 25 percent, and occasional use from 18 to 21 percent.

"We often think of male youth when we talk about drug use, but here female students are driving increases. Historically, their use has been more stigmatized, so normalization may be having a bigger effect," said Zuckermann. "We also see that Indigenous youth start young and have by far the highest rates of current use, factors that will have long-term health implications and need to be addressed."

In 2017-18, rates of lifetime and past-year cannabis use were highest among male (33 and 29 percent) and Indigenous students (55 and 46 percent), and lowest among Asian students (17 and 14 percent). Female students stood at 31 percent for lifetime use and 26 percent in the past year.

"The ability to track multiple risk factors among youth over time and maintain ongoing data systems like COMPASS can provide valuable information to policymakers," added Scott Leatherdale, principal investigator and a professor in the School of Public Health and Health Systems. "It helps to provide the necessary evidence to learn from new policy implementation."


  1. James Tripp James Tripp Canada says:

    The acceptance of the false information that cannabis is detrimental to human health was institutionalized into society many decades ago and unfortunately it takes even longer to unlearn bad information than it does too learn valid information.

    Cannabinoids have been ignored as potent medicines due to the pharmaceutical industry’s failure to successfully isolate and synthesize any beneficial individual cannabinoid compounds;  They have ignored the synergy and entourage effects of the complex of over 100 Cannabinoids and 100s of terpenes in the Cannabis plant due to the industry wide fixation on the current 'Isolate, target, Patent for Profit', system of pharmaceutical research.

    There is a Pervasive, Institutionalized, Negative Bias against all forms of Cannabis Use that has existed for almost a century and is still rampant in virtually all institutions that form the structure of our society and those who populate those agencies are institutionalized to think ideologically and only in terms of addiction and harm reduction, crime and punishment, Patent and Profit…;    In the case of Cannabis they are completely ignoring the abundance of positive heath benefits that the various forms of Whole Plant Cannabinoid Therapy could provide a multitude of individuals, all because it conflicts with established ideological mentality, and/or, it does not fit the current ‘patent and profit’ mandate of pharmaceutical research and production, and marketing.

    Until our Governments, Our Public Institutions, Our Medical professionals and the institutions they represent, Our Law Enforcement Agencies, and society in general, abandon the decades of misinformation and misunderstanding on how the phytocannabinoids in the cannabis plant interact with the Human Endocannabinoid System, we will continue to spend more resources on unnecessary legislation and continued delays instead of implementing proper legislation providing access to the vast medicinal potential of this very safe and effective medicinal plant and health supplement.

    • Colin Bentley Colin Bentley United Kingdom says:

      While agreeing with most of what you say about the model that the pharmaceutical companies work on and the presumed bias against cannabis within the article and preoccupation with this. Rather than for example, noting that there appears to be a gender levelling, or asking what social or other reasons might be behind “Indigenous” (what does that even mean exactly?) youth consuming it more often and what effect this might be having on them? Not to forget that the measurement scales usually used for this, follow the same model as the pharmaceutical companies measure their success by e.g. how much money is made after all law suits and other production costs are allowed for?
      However I think it is worth noting that the hitherto illicit cannabis dealers work on precisely the same model as the pharma companies and will continue the same way if/when they do become legal. To this end it has been an advantage to them to concentrate their product/s in order to handle less and gain more. Regardless of the effect it might have on their consumers, so long as they can convince them to consume it.
      There is accumulating evidence that particularly the extraordinarily high THC content plants that skilful breeders have produced, are leading to higher rates of depression and possibly psychosis especially in younger people with still developing brains. Also it appears that it is very often a gateway to a much more devastating drug; tobacco, which is certainly a very strong and complex addiction substance.
      I think the real thing that you put your finger on is basically that psychopaths rule while most people go for a comfortable life. To change that requires a very deep change in our whole social structure to realign our aims if not our whole human character structure. . .

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News-Medical.Net.
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