Marijuana use in undergraduate students: the short-term relationship between motives and frequency of use

Background: Prior to legalization in October 2018, marijuana was the most commonly used illicit drug in Canada, with 60-73% of undergraduate students reporting use over their lifetime. Research consistently links marijuana use to negative outcomes such as physical and mental health problems and social, educational, and occupational impairments. Changes in substance use ensue rapidly in emerging adults, which makes understanding the link between motives and frequency important.Methods: A sample of 410 participants was recruited to complete self-report measures of marijuana motives and frequency of marijuana use at Baseline and Follow-Up (two weeks later). Of the initial sample, 247 reported prior use of marijuana and were included in the analyses. Hierarchical regression analyses were performed to test the relationships between the Baseline marijuana motives and frequency of use at Follow-Up while controlling for Baseline frequency of use.Results: The coping motive was the only motive significantly associated with a greater frequency of future marijuana use after controlling for prior frequency of use.Conclusion: Findings from this study help clarify the link between reasons for using marijuana and the frequency of use - an important area of research given recent legalization in Canada.