Unmet Psychological Needs Drive College Students to Mix Alcohol and Marijuana
College students with lower psychological need satisfaction were more likely to use alcohol and marijuana simultaneously, primarily to cope with stress — and this pattern was strongest among students who expected positive effects from combining the substances.
Quick Facts
What This Study Found
Lower psychological need satisfaction predicted greater simultaneous alcohol-marijuana (SAM) use through calm/coping and social motives, with the coping pathway strengthened among students with higher positive SAM expectancies, suggesting a vulnerability profile for co-use.
Key Numbers
N=822 from 6 universities; 70.2% female; mean age 19.44; coping and social motives mediated PNS→SAM use; moderation significant for coping motives with positive expectancies; predominantly White non-Hispanic (62.9%)
How They Did This
Cross-sectional survey of 822 college students from six US universities who reported past-month SAM use, using moderated mediation models testing psychological need satisfaction, SAM motives (calm/coping, social), and positive SAM expectancies.
Why This Research Matters
Understanding that unmet psychological needs drive co-use through coping motives — especially when amplified by positive expectations — identifies specific intervention targets for reducing risky substance combinations on college campuses.
The Bigger Picture
Rather than just telling students not to mix substances, this research suggests that addressing underlying psychological needs and challenging positive expectancies could be more effective prevention strategies.
What This Study Doesn't Tell Us
Cross-sectional design limits causal inference; self-selected sample of SAM users; predominantly White and female; self-report measures; university sample may not generalize; doesn't capture actual consumption quantities.
Questions This Raises
- ?Would interventions addressing psychological need satisfaction reduce SAM use?
- ?Are coping motives for SAM use different from single-substance coping use?
- ?Do these pathways differ across cultures or non-college populations?
Trust & Context
- Key Stat:
- Evidence Grade:
- Multi-university sample with theoretically grounded mediation analysis, but cross-sectional design and self-selected sample limit causal and generalizability claims.
- Study Age:
- Published 2026; reflects current college substance use patterns.
- Original Title:
- Psychological Need Satisfaction and Simultaneous Alcohol and Marijuana Use: A Moderated Mediation Model of Expectancies and Motives.
- Published In:
- Substance use & misuse, 61(4), 483-490 (2026)
- Database ID:
- RTHC-08334
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Why do college students mix alcohol and marijuana?
This study found that students with unmet psychological needs (autonomy, competence, relatedness) used the combination primarily to cope with stress and for social reasons, especially when they expected positive effects from mixing.
What makes some students more likely to co-use?
The highest-risk combination was low psychological need satisfaction plus high positive expectations about mixing — these students were most likely to use alcohol and marijuana simultaneously for coping purposes.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-08334APA
Herchenroeder, Luke; Krishnamurti, Harini; Dodge, Tonya; Yeung, Ellen. (2026). Psychological Need Satisfaction and Simultaneous Alcohol and Marijuana Use: A Moderated Mediation Model of Expectancies and Motives.. Substance use & misuse, 61(4), 483-490. https://doi.org/10.1080/10826084.2025.2565421
MLA
Herchenroeder, Luke, et al. "Psychological Need Satisfaction and Simultaneous Alcohol and Marijuana Use: A Moderated Mediation Model of Expectancies and Motives.." Substance use & misuse, 2026. https://doi.org/10.1080/10826084.2025.2565421
RethinkTHC
RethinkTHC Research Database. "Psychological Need Satisfaction and Simultaneous Alcohol and..." RTHC-08334. Retrieved from https://rethinkthc.com/research/herchenroeder-2026-psychological-need-satisfaction-and
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.