What Did Young Adults Infer About Combining Cannabis and Alcohol?
The study presented scenarios
McMahon and colleagues recruited 653 Canadian adults aged 18 to 25. Participants rated the potential harm in short fictional scenarios that varied features of cannabis use, including whether the character also used alcohol or tobacco. The study randomly assigned variants within each scenario so the investigators could compare how a change in wording affected the ratings.
Perceived harm and observed harm are separate outcomes
In the co-use scenario, respondents rated cannabis with tobacco as riskier than cannabis alone, but the study found no difference in perceived harm between cannabis with alcohol and cannabis alone. The result concerns what participants inferred from the descriptions. They were not given alcohol or cannabis, and the researchers did not measure driving, balance or other performance.
Why the distinction matters in a case
A person’s belief about the danger of combining products may help explain their decisions. It provides different evidence from a toxicology or performance assessment. An opinion about an actual event needs the exposure history, timing and documented behavior. The study’s ratings give context for how a group understood hypothetical risk.
Source
McMahon et al., Harm Reduction Journal (2023)
