Young adults in the U.S. exhibit the highest rates of cannabis use compared to other age groups, and due to changes in the legal status of cannabis, increased social acceptance, and strengthened public regulations on tobacco use, cannabis is often the first substance they encounter. These contextual factors contribute to cannabis use frequently preceding tobacco use, particularly ENDS, and may exert an influence on the initiation of ENDS use. With ENDS emerging as the predominant form of tobacco consumption among young adults, examining the impact of cannabis use across its various stages has become an essential yet insufficiently explored research area, marked by a notable lack of comprehensive studies. The current study aims to analyze the association between past 30-day cannabis use frequency and transitions in ENDS use among young adults.
The study included 5,018 young adults aged 18–29 from 24 Texas colleges, with data collected over 4.5 years through Project M-PACT. The analysis utilized a continuous-time multi-state Markov model to examine the impact of “past 30-day cannabis use frequency” on ENDS usage transitions (initiation, desistance, re-uptake). The model also accounted for socio-demographic factors and time-varying intrapersonal (e.g., tobacco and alcohol use, sensation-seeking, depressive symptoms) and interpersonal (peer ENDS use) confounders.
According to the findings, cannabis use plays a significant role in influencing the initiation and continuation of ENDS use among young adults. Each unit increase in past 30-day cannabis use frequency was associated with a 24% increase in the likelihood of ENDS initiation, alongside a 5% decrease in the likelihood of cessation. While cannabis use frequency was not significantly correlated with ENDS resumption after cessation, intrinsic factors such as sensation-seeking tendencies and the use of other tobacco products, as well as interpersonal influences like peer ENDS use, contributed to an elevated probability of both ENDS initiation and resumption while simultaneously reducing the likelihood of cessation. These findings highlight concerns that cannabis may enhance nicotine’s rewarding effects, potentially increasing dependence, underscoring the need for targeted prevention strategies to reduce concurrent cannabis and ENDS use among young adults.
Takeaway: Cannabis use drives ENDS initiation and persistence in young adults, underscoring the need for targeted prevention of concurrent use.