Wallingford S, Konefai S, Young MM. 2019 Cannabis Use, Harms and Perceived Risks among Canadian Students. Technical Report. 2019; Ottawa Ont: Canadian Centre on Substance Use and Addiction

Full report

Report at a Glance (two-page summary)


Why was this study conducted?

Cannabis is one of the most widely used psychoactive substances for Canadian youth but it is unclear whether this behaviour will be affected by changes in cannabis legislation and use by adults. To study this issue, the authors combined information from two national and five provincial (British Columbia, Manitoba, Quebec, New Brunswick, and Newfoundland and Labrador) drug use surveys of students (grades 7 to 12, excluding Quebec), conducted between 2007 and 2015.


What does this study add?

Main findings are summarized in the full and summary reports. They include:

  • Overall, student cannabis use is decreasing over time
  • Up to a third of students report past-year use, with males more likely than females to report more frequent use (e.g., monthly, past-month or daily)
  • Students perceived regular use of cannabis as more risky than occasional use, but perceptions of risk decrease with age
  • Approximately one in five students report driving while under the influence of cannabis


Is there anything else I should know?

The study was conducted by combining results from different cross-sectional surveys and so cannot track changes in individual behaviour. The analysis was unable to determine which youth are at increased risk of cannabis use or adverse effects. At the same time, the report may provide an important baseline for tracking changes following legalization.


Author Details

The latest scientific evidence on this topic was reviewed by the Centre's leadership team. This research summary is written by Corinne Hodgson, DHealth, assessed for accuracy by Dr. James MacKillop, PhD. There are no conflicts of interest. Questions regarding this piece should be directed to Dr. James MacKillop (jmackill@mcmaster.ca).