Marijuana use peaked in April and December among young adults, regardless of college status | Research

The takeaway

Monthly surveys of 761 young adults over 24 months found alcohol and marijuana use varied by calendar month, with marijuana use highest in April and December across all educational groups.

Substance use prevention program planners, college health officials, public health communicators

Marijuana use peaked in April and December across all educational groups

What the researchers found

All substance use measures showed calendar month variation. Marijuana use was highest in April and December regardless of educational status. Alcohol use peaked in summer, October, and December. College students drank more per week overall, with the gap widest in September-October, but drinking levels converged across educational groups in summer and December.

Why it matters

Knowing when substance use peaks can help prevention programs time their efforts. The April marijuana peak (coinciding with cannabis culture's "4/20") and December holiday peak suggest cultural and social drivers of use patterns.

The numbers in context

761 participants; 57% female; ages 18-23; 24 monthly surveys; marijuana use highest in April and December; alcohol peaked in summer, October, and December; 4-year college students drank more per week; drinking converged across groups in summer and December

How the study worked

Longitudinal study of 761 community-based young adults (57% female, ages 18-23 at enrollment) surveyed monthly for 24 consecutive months. Multilevel models accounted for nesting of monthly data within individuals. Compared patterns across educational status groups.

What this study cannot tell us

Community sample from one metropolitan area. Self-reported monthly use may not capture within-month variation. 24-month window limits ability to separate year effects from month effects. Cannot determine whether April peak is related to 4/20 specifically.

How to read the evidence

Strong longitudinal design with monthly measurements over 24 months in a diverse sample, though limited to one geographic area.

When this study was published

Published in 2021.

The bigger picture

Seasonal patterns in substance use reflect social, cultural, and academic influences. Understanding these patterns enables more precise targeting of prevention resources rather than spreading them evenly across the year.

Questions still open

Is the April marijuana peak driven by 4/20 celebrations specifically? Would prevention messaging timed to precede high-use months be more effective than year-round campaigns?

Common questions

When do young adults use marijuana most?

April and December showed the highest marijuana use across all educational groups. The April peak likely reflects cultural cannabis celebrations (4/20), while December coincides with holiday socializing.

Did college students use more marijuana?

For alcohol, college students clearly drank more per week. For marijuana, the calendar patterns were consistent across educational status groups, suggesting marijuana use calendars are driven more by cultural factors than academic ones.

Read the original research

Calendar Month Variation in Alcohol and Marijuana Use in a Community Sample of Young Adults.

Journal of studies on alcohol and drugs, 82(2), 169-177

View on PubMed ↗

Citation

Fleming, Charles B; Duckworth, Jennifer C; Patrick, Megan E; Fairlie, Anne M; Abdallah, Devon A; Lee, Christine M. (2021). Calendar Month Variation in Alcohol and Marijuana Use in a Community Sample of Young Adults.. Journal of studies on alcohol and drugs, 82(2), 169-177.