“Tea” time? Cannabis legalization in Canada

Justin Sorge RRT FCSRT MPH

Correspondence: Justin Sorge, Research Associate, Canadian Institute of Substance Use Research, University of Victoria, Victoria, BC, Canada. E-mail: moc.t1531964345rsc@f1531964345eihcn1531964345iroti1531964345de1531964345

This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (http://creativecommons.org/licenses/by-nc/4.0/), which permits reuse, distribution and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes. For commercial reuse, contact moc.t1531964345rsc@r1531964345otide1531964345

Can J Respir Ther 2018;54(2):08


Justin Sorge

Cannabis legalization in Canada is coming this summer. At press, the Cannabis Act, Bill C45, has been approved by the Senate. This legislation, aimed at restricting access for Canadian youth to cannabis while curbing the organized criminal activity associated with the distribution of this illegal substance, will allow Canadian adults to possess up to 30 grams of legal cannabis and grow up to four plants at home [13].

While there is some conclusive evidence supporting cannabis use for treatment of some illnesses—see Whiting et al. [4] and the Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda [5] for further details—the associated risks of use may be of particular interest to our readership.

While difficult to rule out residual confounding with concurrent tobacco use, lifetime combustible cannabis use was associated with a 2.12 hazard ratio of developing tracheal, bronchus, or lung cancer over nonusers [6]. The acute intoxicating effects of use have been associated with a higher risk of motor vehicle collision [79] and marginally associated with fatal and serious injury [10]. Long-term use has been associated with a host of mental health, developmental, and psychosocial outcomes; curious readers are directed to the World Health Organization’s recent comprehensive review of the health effects of cannabis use [10].

To mitigate these risks, Fischer et al. [11] recently updated the Lower Risk Cannabis Use Guidelines in the Canadian context. Following a comprehensive review of the literature, 10 recommendations to reduce the harms associated with use are presented. Health care practitioners of all professions are encouraged to review and familiarize themselves with these guidelines so that they may engage in dialogue with users, or those considering cannabis use, in efforts to mitigate the public health impacts, especially in the context of legalization.

Statistics Canada’s 2017 Canadian Cannabis Survey reveals an overall past 12-month cannabis use prevalence of 21.7%; higher use among males than females was noted; 26.1% compared with 17.5%, respectively. Among age groups, those aged 20–24 years reported highest rates of use, with the age group 16–19 years reporting slightly lower use, and among the 25+ years age group 18.4% reported use [12]. In a survey of substance use among Canadian students in grades 6–12 in 2014–2015, 17% of respondents reported past year cannabis use [13]. During the 2004–2015 period, reported cannabis use trends decreased among 15–17-year-old females and all 18–24 year olds, remained stable among 15–17-year-old males, and showed an increasing trend among individuals of both sexes aged 25 years and older [14]. While steps are often taken to adjust for any bias in self-reported use, it is widely understood that self-reported use of illicit substances is under reported.

These figures, and a forthcoming time series study by our research group on the harms and costs of substance use in Canada, provide a baseline from which to measure the effect of legalization on the epidemiology of cannabis use, health outcomes, crime rates, and socioeconomic factors. Such with other legal psychoactive or habit-forming substances—namely alcohol and tobacco—it is the responsibility of the health care practitioner to remain informed of the most up to date and robust evidence of the benefits, risks, harms, and mitigating factors of cannabis use and to translate this knowledge to their patients in language and a medium that will be accepted and understood.

One benefit of legalization of cannabis in Canada is certain: this research is going to be a lot easier to carry out as more robust data are available for analysis!

Justin Sorge RRT, FCSRT, MPH, Editor-in-Chief


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