Substance use and mental health issues often go hand in hand, but few studies have examined how using multiple substances at once—alcohol, cannabis, and e-cigarettes—affects depression and anxiety in college students. This study analyzed data from 83,467 undergraduate students participating in the 2020–2021 Healthy Minds Survey to explore how exclusive, dual, and polysubstance use correlates with mental health outcomes across racial, ethnic, and gender groups.
Findings show that students who used both cannabis and e-cigarettes (“dual users”) had the highest risk of depression and anxiety, followed by those who used all three substances (“polysubstance users”). The mental health impact was more severe for male students, with dual users experiencing 2.72 times higher odds of depression and 2.23 times higher odds of anxiety compared to those who only used alcohol. In contrast, Black students had lower odds of anxiety and depression compared to White students.
Key Takeaways
- Dual use of cannabis and e-cigarettes poses the highest risk for depression and anxiety, even more than using all three substances together.
- Male students show a stronger association between substance use and mental health risks compared to female students.
- African American students had lower odds of anxiety and depression compared to White students, suggesting potential protective factors or differences in reporting.
- Findings highlight the need for targeted mental health interventions for students engaging in dual or polysubstance use.
- Implications
- This study suggests that mental health risks associated with substance use are complex and not necessarily additive, meaning using two substances together can be more harmful than using all three.
- College health programs should prioritize screening and intervention efforts for dual substance users, particularly cannabis and e-cigarette users, to mitigate the risk of anxiety and depression among students.
Why this Matters
As mental health challenges increase among college students, this study sheds light on a hidden and urgent concern: the compounding effects of dual substance use. Students who use both cannabis and e-cigarettes are at significantly greater risk for depression and anxiety, even more so than those who use three substances simultaneously. These findings challenge the assumption that more substances always mean more harm and point to specific high-risk combinations that need targeted attention.
The study also reveals that male students may face heightened mental health risks from substance use, suggesting a need for gender-responsive interventions. Notably, Black students reported lower rates of anxiety and depression, raising important questions about protective cultural, social, or reporting factors that could inform future mental health strategies.
By identifying patterns of risk among specific student populations, colleges and health professionals can better tailor screening, outreach, and support programs, especially for students engaged in dual use of cannabis and e-cigarettes. These insights are key to reducing the burden of mental health issues on campuses nationwide.
–Camillia Lui, PhD, lead author and scientist
Read the full study: Lui, C. K., Jacobs, W., & Yang, J. S. (2024). Patterns of Alcohol, Cannabis, and E-Cigarette Use/Co-Use and Mental Health Among U.S. College Students. Substance Use & Misuse, 60(1), 108–119.
