Cannabis knowledge and health literacy among Thai vocational students: a cross-sectional study following policy liberalization

Abstract Background Thailand’s decriminalization of cannabis in June 2022 substantially increased adolescent exposure. Cannabis knowledge and health literacy among vocational students remain poorly characterized. Methods A cross-sectional online survey was conducted from January to March 2024 among vocational secondary students at one vocational institution in a province in northeastern Thailand. Of 2,656 eligible students, 555 provided valid responses (response rate 20.9%). Two 15-item instruments were used to measure cannabis knowledge and cannabis health literacy. Bivariate analyses and three multivariable regression models examined factors associated with knowledge scores, health literacy scores, and cannabis use experience. Results Cannabis knowledge was low (mean 7.23/15, SD 4.43; 55.0% low), as was cannabis health literacy (mean 41.72/75, SD 12.72; 48.8% low). Knowledge level was not significantly associated with health literacy level (χ24 = 7.04, p = 0.134). In adjusted analyses, prior cannabis education and other substance use were associated with higher knowledge scores, whereas male sex and Year 3 enrollment were associated with lower knowledge scores. Higher health literacy scores were associated with prior cannabis education and family relationship quality in adjusted analyses; male sex showed only a weak adjusted association with lower health literacy. Cannabis use experience was associated with other substance use (OR 4.115), prior cannabis education (OR 3.683), male sex (OR 2.621), Year 2 enrollment (OR 1.733), and family relationship quality (OR 1.558). Conclusions Cannabis knowledge and health literacy were predominantly low among Thai vocational secondary students. Factual knowledge alone may not translate into functional cannabis health literacy. School-based interventions should strengthen critical appraisal, communication, self-management, and digital health literacy, with attention to male students, students without prior cannabis education, and those with other substance use experience.