Reprinted with permission from the Canadian Medical Association Journal

With tabling of Bill C-45, the federal government has moved one step closer to fulfilling its election promise to legalize the use of cannabis in Canada, despite concerns over the many health risks associated with its use. The purported purpose of the act is to protect public health and safety,1 yet some of the act’s provisions appear starkly at odds with this objective, particularly for Canada’s youth.

Simply put, cannabis should not be used by young people. It is toxic to their cortical neuronal networks, with both functional and structural changes seen in the brains of youth who use cannabis regularly.2 The Centre for Addiction and Mental Health has stated unequivocally that “cannabis is not a benign substance and its health harms increase with intensity of use.”3 Although adults are also susceptible to the harmful effects of cannabis, the developing brain is especially sensitive. The Canadian Paediatric Society cautions that marijuana use in youth is strongly linked to “cannabis dependence and other substance use disorders; the initiation and maintenance of tobacco smoking; an increased presence of mental illness, including depression, anxiety and psychosis; impaired neurological development and cognitive decline; and diminished school performance and lifetime achievement.”2 The lifetime risk of dependence on marijuana is about 9%; however, this increases to almost 17% in those who start using as teenagers.4

Bill C-45 draws on the work of the federal Task Force on Cannabis Legalization and Regulation that recommended taking a public health approach to the regulation of cannabis to minimize associated harms.5 Yet, in the bill, the federal government has set the national minimum age for purchase of marijuana at 18 years with no limits on potency and allows for personal cultivation of cannabis for nonmedical purposes.1Failure to set national standards for distribution also opens the door to substantial variation in ease of access.

Drawing on current evidence that suggests that the human brain appears to mature until about age 25 years, the Canadian Medical Association (CMA), in its response to the federal task force report, recommended that the minimum age of purchase and consumption be set at 21 years.4 Along with others, the CMA also called for restricting cannabis quantities and potency for those under the age of 25 years, because higher potency increases the risk of adverse effects.24 These pragmatic recommendations balance protection of the developing brain with the hope of reducing use of illicit cannabis among youth.

The federal government has stepped back from setting national standards for retail distribution systems.1 Because provinces and territories are mandated to set their own regulations, ease of access to cannabis will likely differ across the country and include various combinations of mail order, online sales, storefront shops, liquor stores and other modes of access. These differences will complicate enforcement, particularly at jurisdictional borders, and may contribute to diversion. And it is naive to think that organized crime will not be involved in the legal production and distribution of cannabis with the passing of Bill C-45, because it is already implicated in the medical marijuana industry.6

Bill C-45 allows for personal cultivation of up to four marijuana plants, each no more than 1 m in height.1 Because marijuana plants can grow to a height of 6 m, the height restriction will substantially reduce each plant’s yield (although shorter cultivars are sure to be in the offing). However, allowing personal cultivation will increase the risk of diversion and access to cannabis that is not subject to any quality or potency controls.6This is not consistent with the act’s goals of establishing strict safety and quality requirements for cannabis and restricting its access to youth.1 In addition, allowing personal cultivation places pressure on law enforcement officials in interpreting and enforcing these regulations.6

Most of us know a young person whose life was derailed because of marijuana use. Bill C-45 is unlikely to prevent such tragedies from occurring — and, conversely, may make them more frequent. Although an accompanying bill lays out stronger penalties for impaired driving and proposed limits for blood levels of tetrahydrocannabinol in drivers, there is grave concern that legalization of marijuana will result in a substantial increase in impaired driving, particularly among young people and in conjunction with alcohol use.6

The government appears to be hastening to deliver on a campaign promise without being careful enough about the health impacts of policy. It’s not good enough to say that provinces and territories can set more stringent rules if they wish. If Parliament truly cares about the public health and safety of Canadians, especially our youth, this bill will not pass.


  1.  Bill C-45. First Session, Forty-second Parliament, 64-65-66 Elizabeth II, 2015–2016–2017. Available: (accessed 2017 May 7).
  2.  Cannabis and Canada’s children and youth [position statement]. Ottawa:Canadian Paediatric Society; 2016. (accessed 2017 May 7).
  3.  Cannabis Policy Framework. Toronto: Centre for Addiction and Mental Health;2014. (accessed 2017 May 7).
  4.  Legalization, regulation and restriction of access to marijuana. Ottawa:Canadian Medical Association; 2016. Available: (accessed 2017 May 7).
  5.  A framework for the legalization and regulation of cannabis in Canada: the final report of The Task Force on Cannabis Legalization. Ottawa: Health Canada;2016.
  6.  CACP discussion paper — recommendations of the Task Force on Cannabis Legalization and Regulation, February 8, 2017. Kanata (ON): Canadian Association of Chiefs of Police; 2017. Available: (accessed 2017 May 7).

Reprinted with permission from the Canadian Medical Association Journal