Can e-cigarette use increase the risk of marijuana use?

In addition to the harm caused by nicotine, e-cigarette use may also increase the likelihood of teenagers and young adults using marijuana, according to a recent meta-analysis.

Researchers performed a review of information in PubMed, Embase, and Web of Science & ProQuest Dissertations and Theses, covering each database from inception to October 2018. They included studies that compared the rates of marijuana use among children, teenagers, and young adults aged 10 to 24 years who had used e-cigarettes versus those who had not used e-cigarettes.

Of the 835 identified studies, 21 met the researchers’ selection criteria. The studies included 3 longitudinal and 18 cross-sectional studies and included 128,227 participants. The odds of marijuana use were higher among participants who had a history of e-cigarette use versus those who had no history (adjusted odds ratio [AOR], 3.47 [95% confidence index {CI}, 2.63-4.59]; I², 94%). The odds of marijuana use in participants with a history of e-cigarette use being significantly increased was found in the cross-sectional studies (AOR, 3.70 [95% CI, 2.76-4.96]; I², 94%) and the longitudinal studies (AOR, 2.43 [95% CI, 1.51-3.90]; I², 74%). The studies also showed the odds of marijuana use with a history of e-cigarettes was higher in teenagers aged 12 to 17 years versus young adults aged 18 to 24 years (AOR, 4.29 [95% CI, 3.14-5.87]; I², 94% vs AOR, 2.30 [95% CI, 1.40-3.79]; I², 91%).

The researchers concluded that e-cigarette use led to a significant increase in the odds of past or current marijuana use. They argue that the findings add another reason to address the rampant e-cigarette use in teenagers and young adults.