Cannabis and Tobacco Co-Use and Cannabis Dependence: A Survey of US Adults in Legal Recreational Cannabis Markets

Cannabis and tobacco are frequently used together, yet health risks may differ by mode of co-use. This study examined patterns of cannabis/tobacco co-use and their associations with problematic cannabis use in legal U.S. markets. We surveyed 2978 adults (aged 21+) who used cannabis in the past 30-d and lived in states with legalized recreational cannabis. Participants were categorized as cannabis-only, concurrent (separate use), simultaneous-only (co-administration), or combined co-use (both). We assessed cannabis problems using the Cannabis Use Disorder Identification Test-Revised (CUDIT-R) and evaluated associations using adjusted linear regression for demographics and use frequency. We also explored motivations for use and reasons for co-use. Two-thirds of participants engaged in cannabis/tobacco co-use, with over half using simultaneous modes. Participants who engaged in combined and simultaneous-only use had higher CUDIT-R scores than cannabis-only use, even after adjustment. Blunt smoking predominated among participants using simultaneous-only forms, while people combining co-use forms reported a broader range of modes. Motivational factors partially explained the link between co-use and cannabis problems. Co-use patterns – particularly simultaneous use – are associated with more severe cannabis problems than cannabis-only use. These findings underscore the importance of tailored interventions that consider timing, mode, and motivation behind co-use behaviors to reduce the severity of cannabis-related problems.