Teens Frequently Exposed to Cannabis and Vaping on Social Media Were More Likely to Start Using

California high school students who frequently saw e-cigarette and cannabis posts on social media were significantly more likely to start using these substances, with posts from friends and micro-influencers showing the strongest associations.

Vassey, Julia et al.·JAMA network open·2025·Moderate Evidencelongitudinal
RTHC-07857LongitudinalModerate Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
longitudinal
Evidence
Moderate Evidence
Sample
N=4,232

What This Study Found

Frequent exposure to e-cigarette and/or cannabis social media posts at baseline was associated with higher odds of initiating e-cigarette, cannabis, and dual use at one-year follow-up among never-users. Posts from friends and micro-influencers showed the strongest associations with use.

Key Numbers

Study 1: 4,232 adolescents (mean age 17.0, 52.1% female). 22.9% reported frequent baseline exposure. Study 2 examined exposure from five source types. Both conducted among California high school students.

How They Did This

Two studies: (1) a longitudinal study of 4,232 California high school students with one-year follow-up among baseline never-users, and (2) a cross-sectional survey examining exposure to posts from specific sources (friends, celebrities, micro-influencers, brands). Both used generalized estimating equations adjusted for sociodemographic and behavioral factors.

Why This Research Matters

Published in JAMA, this study provides strong evidence that social media exposure to cannabis and e-cigarette content predicts actual substance use initiation in teens — not just intentions but real behavior change over one year.

The Bigger Picture

This JAMA-published research strengthens the case for regulating substance-related content on social media platforms. The finding that micro-influencers and friends — not just brands — drive use initiation suggests regulations targeting only commercial advertising may be insufficient.

What This Study Doesn't Tell Us

Observational design — social media exposure may reflect existing interest. California-specific. Self-reported substance use and social media exposure. Cannot determine which specific posts or platforms are most influential.

Questions This Raises

  • ?Would restricting substance-related social media content reduce teen initiation rates?
  • ?How do algorithms amplify cannabis and vaping content for teens?
  • ?Should micro-influencer substance marketing face the same regulations as brand advertising?

Trust & Context

Key Stat:
Evidence Grade:
Longitudinal design with one-year follow-up among never-users provides stronger evidence than cross-sectional studies, published in a top-tier journal with appropriate adjustments.
Study Age:
Published 2025, baseline data from 2021–2023.
Original Title:
E-Cigarette and Cannabis Social Media Posts and Adolescent Substance Use.
Published In:
JAMA network open, 8(6), e2517611 (2025)
Database ID:
RTHC-07857

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Does seeing cannabis on social media cause teens to try it?

The longitudinal design shows that exposure precedes initiation, strengthening the case for a causal link. However, observational studies cannot fully rule out that teens already curious about substances seek out this content.

Which social media sources had the biggest influence?

Posts from friends and micro-influencers (1,000–100,000 followers) showed the strongest associations with substance use, suggesting peer and relatable influencer content may be more impactful than celebrity or brand marketing.

Read More on RethinkTHC

Cite This Study

RTHC-07857·https://rethinkthc.com/research/RTHC-07857

APA

Vassey, Julia; Cho, Junhan; Vogel, Erin A; Iyer, Trisha; Chen-Sankey, Julia; Unger, Jennifer B. (2025). E-Cigarette and Cannabis Social Media Posts and Adolescent Substance Use.. JAMA network open, 8(6), e2517611. https://doi.org/10.1001/jamanetworkopen.2025.17611

MLA

Vassey, Julia, et al. "E-Cigarette and Cannabis Social Media Posts and Adolescent Substance Use.." JAMA network open, 2025. https://doi.org/10.1001/jamanetworkopen.2025.17611

RethinkTHC

RethinkTHC Research Database. "E-Cigarette and Cannabis Social Media Posts and Adolescent S..." RTHC-07857. Retrieved from https://rethinkthc.com/research/vassey-2025-ecigarette-and-cannabis-social

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.