College students who vaped cannabis were influenced by peers who also started vaping, not just peers who used any cannabis
Among 1,313 college freshmen, 5.9% initiated vaping cannabis during their first year, predicted specifically by having peers who also started vaping cannabis rather than peers who used cannabis or e-cigarettes in any form.
Quick Facts
What This Study Found
Researchers tracked 1,313 first-year college students using social network methods to understand the emerging trend of vaping cannabis. By the second survey, 9.4% had vaped cannabis in their lifetime but not recently, 7.5% were current vapers, and 5.9% initiated vaping cannabis between the two surveys.
The strongest predictor of initiating cannabis vaping was having peers in one's social network who also initiated cannabis vaping during the same period. Notably, simply having peers who used cannabis in any form or peers who used e-cigarettes was not sufficient. It was specifically peers who started vaping cannabis that predicted initiation.
Prior experience with both cannabis (any form) and electronic nicotine delivery systems also predicted cannabis vaping initiation. This suggests that cannabis vaping represents a convergence of two existing behaviors, cannabis use and vaping, rather than an entirely new behavior.
Key Numbers
1,313 first-year college students surveyed. 9.4% had vaped cannabis lifetime but not recently. 7.5% were current cannabis vapers. 5.9% initiated between surveys. Prior cannabis use, prior ENDS use, and peers who initiated cannabis vaping all predicted initiation. General cannabis-using or ENDS-using peers did not predict initiation.
How They Did This
Longitudinal study of 1,313 first-year college students surveyed at two time points during their first year, using social network methods to map peer relationships and substance use. Surveys were available for two weeks beginning in the sixth week of each semester. Predictors of cannabis vaping initiation were analyzed.
Why This Research Matters
Cannabis vaping has grown rapidly, particularly among young adults, and involves higher-potency THC concentrates. Understanding the specific peer influence pathway, that it is specifically cannabis-vaping peers who drive initiation, can inform targeted prevention strategies on college campuses.
The Bigger Picture
Cannabis vaping represents a new frontier in both cannabis use and electronic device use. The finding that peer influence is specific to the behavior (vaping cannabis, not just using cannabis or vaping nicotine) suggests that social norms around vaping cannabis are forming as a distinct behavior, not simply an extension of existing substance use patterns.
What This Study Doesn't Tell Us
The study was conducted at a single university and may not represent all college populations. Self-reported cannabis vaping may be underreported. The social network methods capture nominated peers but may miss other influential relationships. The two-wave design cannot capture more nuanced temporal dynamics. Cannabis vaping products and prevalence have changed since the study.
Questions This Raises
- ?Are college students who vape cannabis aware of the higher THC concentrations in vape products?
- ?Could targeted interventions for cannabis-vaping peer groups be more effective than general prevention?
- ?Has the EVALI crisis changed cannabis vaping patterns on college campuses?
Trust & Context
- Key Stat:
- Peer cannabis vaping initiation, not general cannabis or e-cig use, predicted starting
- Evidence Grade:
- This is a moderate-sized longitudinal study with social network methods, providing moderate evidence for specific peer influence pathways in cannabis vaping.
- Study Age:
- Published in 2018, before the EVALI vaping illness outbreak of 2019 which significantly changed the landscape.
- Original Title:
- Initiation of vaporizing cannabis: Individual and social network predictors in a longitudinal study of young adults.
- Published In:
- Drug and alcohol dependence, 188, 334-340 (2018)
- Authors:
- Cassidy, Rachel N(2), Meisel, Matthew K, DiGuiseppi, Graham, Balestrieri, Sara, Barnett, Nancy P
- Database ID:
- RTHC-01615
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
How common is cannabis vaping in college?
In this 2018 study, about 17% of first-year college students had vaped cannabis at some point, and 5.9% started during their first year. Rates have likely changed since, particularly after the 2019 vaping illness outbreak.
What predicts starting to vape cannabis?
Three factors predicted cannabis vaping initiation: prior cannabis use, prior e-cigarette use, and having friends who also started vaping cannabis. Interestingly, simply having friends who used cannabis or e-cigarettes in other forms was not sufficient. It was specifically the cannabis vaping behavior in peers that mattered.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01615APA
Cassidy, Rachel N; Meisel, Matthew K; DiGuiseppi, Graham; Balestrieri, Sara; Barnett, Nancy P. (2018). Initiation of vaporizing cannabis: Individual and social network predictors in a longitudinal study of young adults.. Drug and alcohol dependence, 188, 334-340. https://doi.org/10.1016/j.drugalcdep.2018.04.014
MLA
Cassidy, Rachel N, et al. "Initiation of vaporizing cannabis: Individual and social network predictors in a longitudinal study of young adults.." Drug and alcohol dependence, 2018. https://doi.org/10.1016/j.drugalcdep.2018.04.014
RethinkTHC
RethinkTHC Research Database. "Initiation of vaporizing cannabis: Individual and social net..." RTHC-01615. Retrieved from https://rethinkthc.com/research/cassidy-2018-initiation-of-vaporizing-cannabis
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.