Correlates of adolescent sole-, dual- and poly-use of cannabis, vaped nicotine, and combusted tobacco.

Background: Compared to single substance use, adolescents' use of multiple substances is associated with more severe dependence, cessation outcomes, and health risks. This study examined correlates of use and co-use of e-cigarettes, combusted tobacco, and cannabis among high school-aged (9th-12th grade, approximately aged 14-18) adolescents.

Methods: We analyzed the 2019 Massachusetts Youth Health Survey (MYHS) data to calculate the weighted means of any past 30-day sole-use of e-cigarettes, sole-use of combusted tobacco, sole-use of cannabis, dual-use of two of the above substances, and poly-use of all three substances. We then used weighted multinomial logistic regression to examine the associations between demographic, social and behavioral factors and sole-, dual-, and poly-use (vs. no use) of these substances.

Results: Among N = 1614 respondents, any past 30-day dual-use of e-cigarettes and cannabis was the most prevalent (17.2%, SE: 1.3%). Sole-use of combusted tobacco was less than 1%, whereas 4.5% (SE: 0.7%) of respondents reported poly-use of e-cigarettes, cannabis, and combusted tobacco. Lower academic grades and self-reported depression (1 item on persistent feelings of sadness or hopelessness) were associated with increased odds of dual-use of e-cigarettes and cannabis and poly-use (vs. sole-use of any substance). Adolescents who self-reported having "any long-term emotional problems or learning disabilities" had greater odds of poly-use.

Conclusion: Different sets of correlates were associated with sole-, dual-, and poly-use, suggesting that certain adolescents may be more vulnerable than others to multiple substance use. Future research should examine potentially modifiable upstream influences, such as the home environment and socioeconomic factors that may affect the relationship between adolescent mental health, school performance, and multiple addictive substance use.