A ccording to the 2017 Canadian Tobacco Alcohol and Drugs Survey, 15% of Canadians aged 15 years and older reported using cannabis in the past year, the same percentage as for current cigarette use. 1 Approximately 78% of respondents reported consuming alcohol in the past year and 24% reported heavy drinking. 1 Overall, substance use was highest among males aged 20-24 years. 1 There is substantial evidence that cannabis use is associated with motor vehicle collisions, decreased birthweight (if consumed during pregnancy), chronic bronchitis episodes (if cannabis is inhaled), psychotic symptoms and disorders, and cannabis addiction. 2-6 The lifetime risk of cannabis abuse (recurrent use) or dependence (symptoms of tolerance and withdrawal) among Canadians was 6.8% in 2012, and 1.3% of Canadians met criteria for cannabis abuse or dependence in the past year. 6 Moreover, the potency of illicit cannabis increased from 4% in 1995 to 12% in 2014, with higher potency associated with increased risk of adverse health outcomes. 7-11 In general, people who use cannabis more frequently and at a younger age are at higher risk for harm. 11,12 In an effort to promote responsible use, deter criminal activity and protect public health and safety, the federal government legalized nonmedical use of cannabis on Oct. 17, 2018. 13 Cannabis use for medical purposes has been legal in Canada since 2001. 14 The evidence from the United States