Vaping Nicotine and Cannabis at the Same Time Led to More Vaping of Both
Young adults who vaped nicotine and cannabis on the same occasion reported the highest vaping intensity for both substances, suggesting that same-occasion co-vaping is a particularly high-risk pattern.
Quick Facts
What This Study Found
On days with same-occasion co-vaping, participants reported the greatest intensity of both nicotine and cannabis vaping compared to all other patterns (single-substance vaping, same-day different-occasion co-vaping, or non-vaping days). Same-day different-occasion co-vaping also showed higher intensities than single-substance vaping.
Key Numbers
n=111; 30-day daily assessment; 2,522 total daily assessments; 84.7% reported co-vaping in past 30 days; 42.7% nicotine-only days; 9.7% cannabis-only days; 16.5% same-day different-occasion co-vaping; 16.9% same-occasion co-vaping.
How They Did This
Smartphone-based daily diary study collecting 30 consecutive days of vaping behavior from 111 California young adults (aged 18-29) who vaped at least 20 days per month. Generalized linear mixed-effects models examined day-level associations between vaping patterns and vaping intensity, controlling for covariates.
Why This Research Matters
Understanding which co-use patterns carry the most risk is important for targeted intervention. This study identifies same-occasion co-vaping as the highest-risk pattern, which could inform screening tools and cessation messaging for young adults.
The Bigger Picture
As nicotine and cannabis vaping devices become more similar and both substances are increasingly accessible to young adults, co-use patterns are likely to grow. This study provides the first daily-level evidence that temporal proximity of co-use matters for consumption intensity.
What This Study Doesn't Tell Us
Self-reported daily diary data may be inaccurate, particularly for vaping frequency. California-only sample may not represent other regions. Correlational daily-level associations cannot establish causation. Cannot determine whether co-vaping causes higher intensity or higher-intensity vapers are more likely to co-vape.
Questions This Raises
- ?What drives young adults to co-vape on the same occasion rather than separately?
- ?Does same-occasion co-vaping predict escalation to dependence faster than other patterns?
- ?Would interventions targeting same-occasion co-vaping reduce overall consumption?
Trust & Context
- Key Stat:
- Same-occasion co-vaping of nicotine and cannabis produced the highest consumption intensity for both
- Evidence Grade:
- Moderate: Novel daily diary design capturing real-time behavior with statistical modeling, though modest sample size and self-reported data are limitations.
- Study Age:
- Published in 2025 with 2023-2024 data.
- Original Title:
- Vaping nicotine and cannabis on the same occasion is linked to increased vaping consumption among young adults: A smartphone-based daily diary study.
- Published In:
- Drug and alcohol dependence, 266, 112517 (2025)
- Authors:
- Nguyen, Nhung(13), Keyhani, Salomeh(22), Marcus, Gregory M(3), Do, Vuong V, Halliday, Deanna M, Herbst, Ellen D, Ling, Pamela M
- Database ID:
- RTHC-07250
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
What is same-occasion co-vaping?
Same-occasion co-vaping means using both nicotine and cannabis vaping products during the same sitting or activity, as opposed to using them at different times during the same day. This study found it was linked to higher consumption of both substances.
How common is co-vaping among young adults?
In this study, 84.7% of young adult vapers reported co-vaping nicotine and cannabis within the past 30 days. On any given day, about a third of vaping days involved some form of co-use (16.5% different occasion + 16.9% same occasion).
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Cite This Study
https://rethinkthc.com/research/RTHC-07250APA
Nguyen, Nhung; Keyhani, Salomeh; Marcus, Gregory M; Do, Vuong V; Halliday, Deanna M; Herbst, Ellen D; Ling, Pamela M. (2025). Vaping nicotine and cannabis on the same occasion is linked to increased vaping consumption among young adults: A smartphone-based daily diary study.. Drug and alcohol dependence, 266, 112517. https://doi.org/10.1016/j.drugalcdep.2024.112517
MLA
Nguyen, Nhung, et al. "Vaping nicotine and cannabis on the same occasion is linked to increased vaping consumption among young adults: A smartphone-based daily diary study.." Drug and alcohol dependence, 2025. https://doi.org/10.1016/j.drugalcdep.2024.112517
RethinkTHC
RethinkTHC Research Database. "Vaping nicotine and cannabis on the same occasion is linked ..." RTHC-07250. Retrieved from https://rethinkthc.com/research/nguyen-2025-vaping-nicotine-and-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.