Risky cannabis use is associated with varying modes of cannabis consumption: Gender differences among Canadian high school students.

Background: Our objective was to explore associations between indicators of more risky cannabis use (i.e., solitary use, frequent use, and younger age of initiation) and different modes of cannabis use (i.e., smoking, vaping and/or edibles). Methods: Data were gathered from a large sample of Canadian youth in Alberta, British Columbia, Ontario, and Quebec who participated in Year 8 (2019-20) of the COMPASS study, and who reported using cannabis in the past year ( Results: Overall, 38% of students reported using multiple modes of cannabis use. Consistent among both males and females, students who used cannabis alone (35%) and at a higher frequency (55%) were more likely to use multiple modes than smoking only. Among females, those who used cannabis alone were more likely to report using edibles only compared to smoking only (aOR=2.27, 95%CI=1.29-3.98). Earlier cannabis use initiation was associated with lower likelihood of vaping cannabis only among males (aOR=0.25; 95%CI = 0.12-0.51), and lower likelihood of using edibles only among females (aOR=0.35; 95%CI = 0.13-0.95), than by smoking only. Conclusions: Our findings suggest that multiple modes of use may be an important indicator or risky cannabis use among youth, given associations with frequency, solitary use, and age of onset.