Young Adult Concurrent Use and Simultaneous Use of Alcohol and Marijuana: A Cross-National Examination among College Students in Seven Countries

BRAVO, ADRIAN J.; PRINCE, MARK A.; PILATTI, ANGELINA; MEZQUITA, LAURA; KEOUGH, MATTHEW T.; HOGARTH, LEE

Addictive Behaviors Reports

Elsevier

Año: 2021

2352-8532

Many young adults report frequent co-use of alcohol and marijuana, with some individuals engaging in simultaneous use (SAM; use of both substances within the same occasion resulting in an overlap of their effects) and others in concurrent use (CAM; use of both substances during a similar time period [e.g., past 30 days] but not within the same occasion). Emerging work demonstrates that SAM relative to CAM use places individuals at a greater risk for substance-related harms; however, these results primarily rely on U.S. samples. The goal of the present multi-country study was to examine prevalence rates of CAM and SAM use and examine differences in past 30-day SAM/CAM use on alcohol/marijuana substance-related outcomes among college students from seven countries. Methods: A total of 9,171 (70.5% women; Mean age=20.28, SD=3.96) college students participated in the cross-sectional online survey study. Results: Among students who endorsed use of both alcohol and marijuana in the past 30-days (n=2,124), SAM use (75.8%) was far more prevalent than CAM use (24.2%). Moreover, ∼75% of students endorsed SAM use within each country subsample. Regression models showed that SAM vs. CAM use was associated with greater alcohol and marijuana use and negative consequences. Conclusions: College students from around the world endorse high rates of SAM use, and this pattern of co-use is associated with greater frequency of use and substance-related harms. On college campuses, SAM use should be a target of clinical prevention/intervention efforts and the mechanisms underpinning the unique harms of SAM need to be clarified.