Concurrent Alcohol and Marijuana Use Patterns Among High School Seniors in the United States

Concurrent alcohol and marijuana use is common. Knowledge about whether adolescents differ in use frequency across single vs. concurrent use is limited. This study examined past 30-day use patterns by frequency (frequent [20+ occasions] vs. occasional [<20]) and type (single [alcohol or marijuana] vs. concurrent [both]), and tested associations with sociodemographic, psychological/individual, and social-environmental correlates. Data were from high school senior cohorts (2021-2022) from the Monitoring the Future study ( n = 11,003). About 2.2% reported frequent single use, 21.9% occasional single, 3.8% frequent concurrent, 7.7% occasional concurrent, and 64.4% no use. Differences emerged by type and frequency among concurrent users. Frequent concurrent users were more likely to be male, to spend evenings out, to have lower grades, and to smoke cigarettes, but less likely to vape and to live with both parents (vs. occasional concurrent users). Findings reveal distinct correlates of use patterns and identify frequent concurrent users as an at-risk group.