E-cigarette use, dual use of e-cigarettes and tobacco cigarettes, and frequency of cannabis use among high school students

Background The proliferation of electronic vaping products raises many concerns, including whether these products will lead to risky behaviors among adolescents. Evidence suggests that e-cigarettes may be used to vaporize cannabis (marijuana). The current study examined associations between e-cigarette use, dual use of e-cigarettes and tobacco cigarettes, and frequency of cannabis use. Methods Data on high school students (grades 9–12) were from the 2014–2015 Canadian Student Tobacco, Alcohol and Drugs Survey (n = 23,429 respondents). Multinomial logistic regression analyses were used to examine frequency of cannabis use among those who reported using only e-cigarettes, only tobacco cigarettes, both products, and nonusers. Results Approximately 15% of respondents reported using cannabis at least once in the past month. Likelihood of using cannabis was significantly higher for e-cigarette only and cigarette- only users. Users of both products had increased odds for a higher frequency of cannabis use. These results indicated a sequential risk gradient in the use of cannabis for dual use, cigarette only, e-cigarette only, and non-use groups, respectively. Conclusions Youth who reported use of e-cigarettes, tobacco cigarettes, and both products showed a heightened risk of using cannabis more frequently.