Teens who buy cannabis from people or dispensaries use more persistently than those who get it free
Among 835 high school students, those who purchased cannabis from someone or used a valid medical card at a dispensary had significantly higher odds of continued cannabis use six months later.
Quick Facts
What This Study Found
Most youth (72%) received cannabis for free. 51% bought from someone, 16% used a medical card at a dispensary, and 4% grew their own. Buying from someone (OR 1.46) and using a valid medical card (OR 1.99) predicted any cannabis use six months later. Buying from someone also predicted more frequent use (RR 1.25).
Key Numbers
835 high schoolers (mean age ~17). 72.1% received cannabis free. 50.9% bought from someone (OR 1.46 for continued use). 15.9% used valid medical card (OR 1.99). 3.9% self-grown. Buying from someone: RR 1.25 for frequency.
How They Did This
Longitudinal study of 835 high schoolers completing 3 semiannual surveys. Time-lagged repeated-measures regression examined how cannabis sources at one wave predicted use frequency six months later. Seven source types assessed as separate dichotomous variables.
Why This Research Matters
Understanding which access points predict escalation helps target prevention. The finding that medical card access predicted the strongest continued use raises questions about youth medical cannabis authorization.
The Bigger Picture
The finding that medical card dispensary access was the strongest predictor of continued use suggests that legitimate access channels may paradoxically facilitate more persistent patterns of adolescent use.
What This Study Doesn't Tell Us
Self-reported sources. California-based sample during specific legal period. Six-month intervals may miss shorter-term patterns. Cannot determine whether the source caused continued use or whether more committed users seek out purchasing sources.
Questions This Raises
- ?Should medical cannabis authorization for minors include monitoring for escalation?
- ?Does free cannabis access (social sharing) represent a safer pattern because it is less reliably available?
Trust & Context
- Key Stat:
- Medical card use: 2x odds of continued cannabis use
- Evidence Grade:
- Longitudinal design with time-lagged analysis and large adolescent sample, but self-reported and single geographic area.
- Study Age:
- Published in 2022.
- Original Title:
- Associations of cannabis product source and subsequent cannabis use among adolescents.
- Published In:
- Drug and alcohol dependence, 233, 109374 (2022)
- Authors:
- Kelleghan, Annemarie R, Sofis, Michael J(4), Budney, Alan(3), Ceasar, Rachel, Leventhal, Adam M
- Database ID:
- RTHC-03949
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Where do teens get cannabis?
Most (72%) received it for free. About half bought it from someone, 16% used a valid medical card at a dispensary, and 4% grew their own.
Does how teens get cannabis matter?
Yes. Teens who purchased cannabis from someone or used a medical card at a dispensary were significantly more likely to continue using six months later compared to those who received it for free.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03949APA
Kelleghan, Annemarie R; Sofis, Michael J; Budney, Alan; Ceasar, Rachel; Leventhal, Adam M. (2022). Associations of cannabis product source and subsequent cannabis use among adolescents.. Drug and alcohol dependence, 233, 109374. https://doi.org/10.1016/j.drugalcdep.2022.109374
MLA
Kelleghan, Annemarie R, et al. "Associations of cannabis product source and subsequent cannabis use among adolescents.." Drug and alcohol dependence, 2022. https://doi.org/10.1016/j.drugalcdep.2022.109374
RethinkTHC
RethinkTHC Research Database. "Associations of cannabis product source and subsequent canna..." RTHC-03949. Retrieved from https://rethinkthc.com/research/kelleghan-2022-associations-of-cannabis-product
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.