标题：Original quantitative research – Cannabis cessation among youth: rates, patterns and academic outcomes in a large prospective cohort of Canadian high school students
摘要：Introduction: Following cannabis legalization in Canada, a better understanding of theprevalence of unprompted cannabis use reduction and subsequent effects on youth academicoutcomes is needed to inform harm reduction and health promotion approaches.Methods: We analyzed a longitudinally linked sample (n = 91 774) from the COMPASSprospective cohort study of Canadian high school students attending Grades 9–12 inOntario and Alberta between 2013–2014 and 2016–2017. We investigated the prevalenceof spontaneous cannabis use reduction and cessation between grade transitions (Grades9–10, 10–11, 11–12) and the effect of cessation on academic achievement (current orrecent math and English course marks) and rigour (usual homework completion andpast-month truancy).Results: Only 14.8% of cannabis users decreased their use between grades. Of these,two-thirds made only incremental downward changes, a pattern which held true for allthree transitions. Cessation rates from daily and weekly use decreased every year. Aftercessation, students had better odds than continuing users (OR = 1.23, 95% CI: 1.03–1.48) and worse odds than never-users (OR = 0.55, 95% CI: 0.31–0.97) for some subcategoriesof math performance. Students who quit cannabis universally improved classattendance (OR = 2.48, 95% CI: 1.93–3.19) and homework completion (OR = 2.32,95% CI: 1.85–2.92) compared to continuing users.Conclusion: Increased academic rigour may underlie any improvements seen in academicperformance after cannabis cessation. High school students who use cannabislikely need targeted support to facilitate reduction or cessation and subsequent academicrecovery. This indicates that a school-based focus on cannabis harm reductionis justified.
