RecruitingBehavioural interventionA Brief Intervention for Cannabis UseThe purpose of this study is to compare two brief interventions targeting potentially problematic cannabis use in emerging adults (ages 18-25). Brief interventions are two 40-50 minute sessions separated by 1 week. Eligible emerging adults will complete a detailed cannabis assessment (biological and self-report), followed by one of the two brief interventions, and four follow-up assessments: one immediately after the second session and at 1-, 3-, and 6-months post-intervention. Assignment to the brief intervention is random. Salivary samples will be collected at baseline, post-intervention, and all follow-ups, for a total of 5 samples, to be tested for tetrahydrocannabinol (THC) and cannabidiol (CBD).