Background: E-cigarette use is on the rise and many who use e-cigarettes also smoke combustible cigarettes. Dual use (i.e., use of both electronic and combustible cigarettes) is associated with greater rates of cannabis use and cannabis use among individuals who engage in dual use is related to more severe ecigarette-related problems. Yet, no known studies have tested whether cannabis use is related to more severe e-cigarette problems via negative affect and the expectation that e-cigarettes can help manage negative affect. Objectives: The current study tested this hypothesis among 400 adults who endorsed dual use, 33% of whom endorsed current (past three month) cannabis use. Results: Results indicated that participants with cannabis use reported more anxiety, depression, e-cigarette problems, and the following e-cigarette use expectancies: negative consequences, negative reinforcement, and weight concerns. Multiple mediator models found that the relation between cannabis use status and e-cigarette problem severity was mediated by anxiety (but not depression) and by negative reinforcement and weight concerns (but not negative consequences) expectancies. Serial mediator models indicated that the relation between cannabis use and e-cigarette problems occurred via the serial effects of anxiety and negative reinforcement (but not weight concerns) expectancies. Conclusions: These results highlight several clinical correlates of cannabis use among adults who smoke combustible and e-cigarettes, and suggest that anxiety and the expectation that e-cigarettes may help manage such negative emotions play important roles in e-cigarette-related problems among these individuals.
Keywords: E-cigarettes; anxiety; cannabis; depression; dual use; expectancies; marijuana; smoking.