Combining Cannabis, Alcohol, and Energy Drinks on the Same Day Means the Heaviest Drinking and Most Problems
College students who used cannabis, alcohol, and energy drinks on the same day drank more and experienced more negative consequences than on days using any combination of just two substances.
Quick Facts
What This Study Found
Days with simultaneous alcohol + cannabis + energy drinks (SAM+AmED, 15.4% of drinking days) were associated with increased drinking quantity and more negative consequences compared to days with only SAM or only AmED. SAM-only and AmED-only days were also riskier than alcohol-only days.
Key Numbers
21% of drinking days were AmED days, 19% were SAM days, 15.4% were SAM+AmED days. SAM+AmED days had increased drinking and negative consequences vs both SAM-only and AmED-only days. SAM-only and SAM+AmED (but not AmED-only) days had more positive consequences than alcohol-only days.
How They Did This
30-day timeline followback interview with college students who engaged in both simultaneous alcohol-cannabis (SAM) use and alcohol mixed with energy drinks (AmED). Day-level data classified drinking days by substance combination and compared consumption and consequences.
Why This Research Matters
The triple combination of cannabis, alcohol, and energy drinks is common (15% of drinking days) and represents the highest-risk pattern for college students. Identifying this specific pattern helps target prevention efforts at the most dangerous behavior.
The Bigger Picture
Prevention programs typically address substances individually, but this study shows the combination matters. The finding that SAM days had both more negative AND positive consequences suggests students experience rewarding effects that reinforce this risky pattern.
What This Study Doesn't Tell Us
Selected sample of college students who already engage in multi-substance use — not generalizable to all students. Retrospective recall over 30 days. Cannot determine causality or the order of substance use within a day. No measure of quantity for cannabis or energy drinks.
Questions This Raises
- ?Why does adding cannabis to alcohol increase positive consequences as well?
- ?Do energy drinks mask intoxication, leading to more drinking?
- ?Would targeted messaging about the triple combination reduce its occurrence?
Trust & Context
- Key Stat:
- Evidence Grade:
- Day-level analysis with timeline followback provides detailed behavioral data, but selected sample and retrospective design limit generalizability.
- Study Age:
- Published 2025.
- Original Title:
- Simultaneous use of alcohol, cannabis, and energy drinks predicts increased daily alcohol consumption and alcohol consequences.
- Published In:
- Experimental and clinical psychopharmacology, 33(1), 8-15 (2025)
- Authors:
- Waddell, Jack T(3), McDonald, Abigail E, Quiroz, Selena I, Corbin, William R
- Database ID:
- RTHC-07889
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Why is the triple combination so risky?
Each substance affects judgment and consumption differently. Cannabis and energy drinks may both alter perception of intoxication, leading to heavier drinking. The compounding effects on cognition and risk-taking increase the likelihood of negative consequences.
Do energy drinks make the combination worse than just cannabis and alcohol?
Yes — days with all three substances showed more drinking and more negative consequences than days with cannabis+alcohol or alcohol+energy drinks alone.
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Cite This Study
https://rethinkthc.com/research/RTHC-07889APA
Waddell, Jack T; McDonald, Abigail E; Quiroz, Selena I; Corbin, William R. (2025). Simultaneous use of alcohol, cannabis, and energy drinks predicts increased daily alcohol consumption and alcohol consequences.. Experimental and clinical psychopharmacology, 33(1), 8-15. https://doi.org/10.1037/pha0000736
MLA
Waddell, Jack T, et al. "Simultaneous use of alcohol, cannabis, and energy drinks predicts increased daily alcohol consumption and alcohol consequences.." Experimental and clinical psychopharmacology, 2025. https://doi.org/10.1037/pha0000736
RethinkTHC
RethinkTHC Research Database. "Simultaneous use of alcohol, cannabis, and energy drinks pre..." RTHC-07889. Retrieved from https://rethinkthc.com/research/waddell-2025-simultaneous-use-of-alcohol
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.