An examination of how age of onset for alcohol, cannabis, and tobacco are associated with school outcomes in grade 12

Abstract

IntroductionYouth substance use prevention is a key public health priority. There is evidence that delaying substance use can improve health outcomes. While substance use is associated with negative outcomes at school, the benefits of delaying substance use on these outcomes are less well understood. MethodsThe current study examined the substance use behaviours and school outcomes of 35,221 grade 12 students in Canada. Students were asked to report when they began using alcohol, cannabis, and tobacco products as well as school outcomes including school connectedness, math and English grades, truancy, and post-secondary aspirations and expectations. Regression models were used to examine the relationship between of age of initiation of alcohol, cannabis, and tobacco use and these outcomes. ResultsStudents who abstained from substance use throughout high school had higher school connectedness, lower truancy, and higher grades in grade 12 than students who did not. Earlier cannabis use was associated with increased truancy in grade 12. English grades were higher among students who did not use tobacco. Finally, post-secondary educational aspirations and expectations were higher among students who initiated substance use later. ConclusionGrade 12 school outcomes were the best among students who abstained from substance use throughout high school. However, among students who did engage in substance use, school connectedness, truancy, English grades, and educational aspirations and expectations were more favourable among those who initiated substance use at a later age.