In recent years, the pervasive influence of social media on adolescent behavior has become an area of intense scientific scrutiny. New research conducted by the Keck School of Medicine of USC sheds important light on the relationship between social media content featuring cannabis and e-cigarettes and the subsequent substance use behaviors among teens. The findings, published in the prestigious journal JAMA Network Open, underscore the complex and concerning dynamics at play when adolescents engage with digital platforms such as TikTok, Instagram, and YouTube. Their study provides vital evidence demonstrating how exposure to substance-related posts significantly increases the likelihood that teens will start using cannabis, e-cigarettes, or both.
The research unfolds against a backdrop of evolving trends in youth substance use, with reports from authoritative bodies like the U.S. Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) documenting a decline in e-cigarette use among the younger population. Despite this downward trajectory, the persistent social media exposure to e-cigarettes and cannabis-related content continues to fuel initiation and concurrent dual use of these substances. This paradox highlights the need for more nuanced understanding of how digital communication channels propagate and normalize substance use among impressionable audiences.
Julia Vassey, MPH, a health behavior scientist at USC’s Department of Population and Public Health Sciences, emphasizes that although e-cigarette use rates are dropping, the risk engendered by viewing e-cigarette content in social media environments remains pressing, particularly regarding its intersection with cannabis use. Her team’s research involved surveying over 7,600 adolescents through two interrelated studies designed to unravel not only if exposure to social media posts correlates with the initiation or continuation of substance use but also how the nature and source of these posts influence outcomes.
The first longitudinal study focused on temporal associations between frequent exposure to cannabis or e-cigarette posts—defined as at least one post per week—and subsequent initiation of use among teens who previously had no history with these substances. By tracking responses from 4,232 high school students with an average age of 17, the researchers identified that almost 23% regularly viewed e-cigarette-related content, while 12% encountered frequent cannabis-related posts. Intriguingly, those consistently exposed to cannabis posts demonstrated a higher propensity for commencing use of cannabis, e-cigarettes, or both within a year. Conversely, frequent e-cigarette exposure on TikTok was linked to increased initiation of cannabis use or dual substance use.
Notably, these associations were platform-specific. The distinctive algorithmic mechanics and content dissemination methods of TikTok appear to amplify the visibility and attractiveness of such posts more so than Instagram or YouTube. TikTok’s propensity to push trending content broadly—even to users who do not follow the source accounts—may drive this enhanced risk factor, effectively transforming the platform into a potent vector for normalizing and marketing substance use in subtle yet impactful ways.
The second survey study, involving 3,380 students, probed the influence of content origin, distinguishing between posts from brands, celebrities, influencers with mid-tier followings (10,000 to 100,000 followers), and friends. Findings revealed that exposure to cannabis or e-cigarette posts by influencers elevated the likelihood of cannabis use in the preceding month. Meanwhile, posts from friends correlated with dual use or cannabis use, indicating the powerful role of peer networks in influencing substance consumption behaviors. These observations illuminate complex social dynamics in which both formal marketing messages and grassroots peer content converge to shape teen substance use patterns.
A particularly compelling aspect of this research is the identification of “cross-substance associations,” whereby e-cigarette posts increase cannabis use, perhaps due to the visual and functional similarities between devices used for nicotine vaping and cannabis consumption. This finding suggests that the social and psychological contexts fostered by exposure to vaping culture may lower barriers to experimenting with multiple substances, thereby amplifying health risks.
The examination of influencer content reveals a gray regulatory area that complicates efforts to mitigate youth exposure. Federal agencies like the FDA regulate paid promotions where brand partnerships are transparently disclosed; however, influencers often skirt these regulations by omitting disclosures—either unintentionally or deliberately—rendering some of their promotional efforts effectively unsupervised. These “organic” posts tend to be perceived as more genuine and persuasive by adolescent audiences, amplifying their sway in encouraging substance uptake.
In response to the challenges surfaced by this investigation, scholars advocate for more comprehensive regulatory frameworks and platform policies that extend beyond paid advertising bans to include influencer marketing practices. While most platforms currently prohibit explicit paid promotion of cannabis and tobacco products, enforcement gaps and ambiguous guidelines around influencer-generated content leave loopholes exploited by the burgeoning cannabis and e-cigarette markets online.
Looking forward, Julia Vassey plans to delve further into the nuances of cannabis influencer marketing, exploring how evolving social media policies may alter adolescents’ exposure and reactions to substance-related content. This ongoing work is critical for informing evidence-based interventions and for guiding stakeholders—including federal regulators, social media companies, parents, and schools—in devising effective strategies to protect youth from the subtle normalization and glamorization of substance use in digital spaces.
This research also aligns with broader public health objectives aimed at reducing adolescent substance abuse and its myriad adverse outcomes. By illuminating the pathways through which social media content catalyzes initiation and sustained use, the study equips policymakers and public health advocates with scientific evidence necessary to navigate an increasingly complex digital marketing ecosystem targeted at at-risk youth populations.
Moreover, as e-cigarettes and cannabis both occupy evolving and often contested regulatory spheres—marked by shifting legal statuses, social perceptions, and technological innovation—the insights from this study provide a timely lens into how youth culture and consumption patterns may adapt or resist emerging controls. The dynamic interplay of algorithm-driven platform design, influencer marketing tactics, and peer socialization mechanisms signals the necessity of multidisciplinary approaches to youth substance use prevention.
In sum, this groundbreaking investigation integrates behavioral science, epidemiology, and communication studies to map a critical link between social media exposure and adolescent substance use. It highlights the formidable influence of TikTok as a vector for behavioral risk, the potent role of influencers and peer networks in shaping use trajectories, and the pressing need for improved regulatory clarity in the digital domain. As social media continues to permeate daily life, understanding and addressing its impact on teen health behaviors remains a pivotal challenge for society.
Subject of Research: People
Article Title: E-Cigarette and Cannabis Social Media Posts and Adolescent Substance Use
News Publication Date: 24-Jun-2025
Web References: https://doi.org/10.1001/jamanetworkopen.2025.17611
References:
Vassey J, Cho J, Iyer T, Unger JB, Vogel EA, Chen-Sankey J. E-Cigarette and Cannabis Social Media Posts and Adolescent Substance Use. JAMA Network Open. 2025; DOI: 10.1001/jamanetworkopen.2025.17611.
Keywords: Age groups, Drug abuse, Substance related disorders, Social media
