Drug and alcohol use in Canada: Postsecondary students

Data source

This data tool uses data from the Canadian Postsecondary Education Alcohol and Drug Use Survey (CPADS). It includes all three cycles of the survey (see Table 1 below). To increase comparability between cycles, the results in this data tool focus on 17- to 25-year-olds.

Table 1: Sample size of each cycle of the Canadian Postsecondary Education Alcohol and Drug Use Survey (CPADS)

Eligibility criteria

• School eligibility: For schools to be eligible, they had to:
  1. have a registrar office
  2. have more than 500 students
  3. be a not-for-profit or private school
  4. not offer exclusively online courses
  5. be non-theological or non-military institutions
• Student eligibility: For students to be eligible, they had to be at least 16 years old and studying online or in-person in Canada.

Weighting

This analysis used survey weights to ensure the data are representative of the student population at each school by sex and age. Results from each school were then further weighted to align with the overall student population of the regions captured in the survey.

Limitations

• Data availability differs by cycle:
  • 2019-20: No data were available from British Columbia, Saskatchewan, or the territories.
  • 2021-22: No data were available from the territories.
  • 2024-25: No data were available from the Northwest Territories or Newfoundland and Labrador.
• The survey title reveals that the survey is about substance use. This could have attracted respondents who are already more interested or knowledgeable about the topic, which might have affected the results.
• CPADS relies on self-reported data, which may contain some inaccuracies. People filling out the survey may misremember, make mistakes when entering information, or answer in ways they think are more socially acceptable.

Data analysis and reporting

• Estimates are based on students aged 17 to 25 years old.
• Due to rounding, percentages may not add up to exactly 100.
• Analysts used the modified Wilson method to construct confidence intervals.
• Some data cannot be reported because of small sample sizes. Data were only reported if there were at least 50 observations in the denominator. Data that cannot be reported are not displayed in the data tool to protect participant privacy or to avoid unreliable results. These appear as ‘suppr.’.
• Responses from students in the same school tend to be similar, or “correlated”. To account for this and avoid underestimating variability, the analysis treated each school as a primary sampling unit and applied a cluster-based variance correction to reflect the complex survey design. The CPADS survey is not based on random sampling as schools and students choose whether to participate (“self-selection”). Because of this, the variance estimates should be interpreted with caution, as they may differ from the true variance.
• Important note: Estimates and variances in this tool may differ from earlier CPADS publications due to differences in denominators and the use of the cluster-based variance correction.

Key definitions

• Gender diverse: includes non-binary gender, gender-fluid, and other accepted write-in responses.
• ASSIST: An international group of researchers specialised in higher-risk substance use developed the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) for the World Health Organization (WHO) to help detect and manage substance use and related problems in primary and general medical care settings. The CPADS cannabis module adopts questions from ASSIST to screen respondents for higher-risk cannabis use. Respondents are categorised based on their consumption as follows:
  1. Low risk of developing health and other problems (score of 0-3)
  2. Moderate risk of developing health and other problems (score of 4-26)
  3. High risk of developing health and other problems and indicative of a substance dependence (score of 27+)