Through the haze: a multinational cross-sectional comparison of cannabis risk knowledge gaps among young adults

Young adults report heightened cannabis use yet show gaps in cannabis-related risk knowledge. Risk knowledge gaps in young adults with diverse cannabis use experience and across countries with varying cannabis policies, as well as associations with knowledge levels were explored. The International Cannabis Policy Study (ICPS) is a cross-sectional, web-based survey that uses non-probability sampling and post-stratification weighting. Data from the 2023 ICPS national surveys conducted in Canada, Germany and the UK were used. A total of n = 2,945 18- to 25-year-olds were included in the analyses (Canada: n = 2,047; Germany: n = 446; UK: n = 452). Risk knowledge gaps were assessed through 7 health-related risk items. Inaccurate responses were turned into an index variable to measure participants’ level of risk knowledge. Negative binomial regression models were used to examine associations between sociodemographic and use-related variables and knowledge level. Risk knowledge levels were highest among German participants, and lowest among UK participants. Some risks were better known than others across all countries. Risk knowledge was lowest among regular cannabis consumers, for whom being from the UK was associated with decreased knowledge levels (IRR = 1.227) and being at moderate risk of harm from use was associated with increased knowledge levels (IRR = 0.701). Among occasional consumers, age (IRR = 1.041), being male (IRR = 1.222) and being at moderate (IRR = 1.236) and high (IRR = 1.818) risk of harm from use were associated with decreased risk knowledge, whereas peer use (IRR = 0.718) was associated with increased risk knowledge. This study showed that there are differences in the perception of cannabis risks among young adults, which are associated with individual consumption patterns as well as country-specific and sociodemographic factors. Findings extend the current understanding of differences and similarities in risk knowledge gaps among young adults across different countries, allowing for a more tailored risk education towards the needs of this target group.