Cannabis-related school discipline incidents increased 34% after Massachusetts decriminalized cannabis but then dropped 45% after medical legalization and another 20% after recreational legalization.
Education policy makers, school administrators, researchers studying legalization impacts on youth, and harm-reduction advocates.
Cannabis school discipline fell 45% after medical legalization
What the researchers found
Decriminalization was associated with a 34% increase in cannabis-related disciplinary incidents in schools. However, medical legalization reversed this trend with a 45% decrease, and recreational legalization produced a further 20% decrease compared to the prior policy period.
Why it matters
There is widespread concern that cannabis legalization will increase youth problems in schools. This study suggests the opposite occurred in Massachusetts, with discipline rates declining as policies expanded.
The numbers in context
Decriminalization (2008-2011): 34% increase (IRR 1.34). Medical legalization (2012-2015): 45% decrease (IRR 0.55). Recreational legalization (2016-2019): 20% decrease (IRR 0.80). Average incidents per district: 4.6, 4.7, and 5.1 across the three periods.
How the study worked
Multilevel time-series analysis of 2005-2019 data from all 399 Massachusetts public school districts, examining cannabis-related disciplinary incidents per 1,000 students across three policy periods.
What this study cannot tell us
Observational study cannot prove policy changes caused the discipline trends. Discipline practices may have shifted independently of cannabis policy. Data does not capture actual cannabis use, only disciplinary responses.
How to read the evidence
15 years of statewide school district data with appropriate interrupted time-series analysis. Cannot separate policy effects from concurrent changes in school discipline practices.
When this study was published
Published in 2025, data 2005-2019.
The bigger picture
These findings challenge the assumption that cannabis policy liberalization automatically translates to more youth cannabis problems in schools, and support harm-reduction approaches to school discipline.
Questions still open
- Did actual cannabis use among students change, or just how schools responded to it? Would these patterns replicate in other states with different policy timelines?
Common questions
Did cannabis legalization increase school discipline problems?
Why might school discipline decrease after legalization?
Read the original research
Associations Between Evolving Cannabis Policies and Cannabis-Related School Discipline Among Secondary School Students in Massachusetts, 2005-2019.
American journal of preventive medicine, 70(4), 108129
Citation
English, Faith; Laws, Holly B; Yi, Youngmin; Martínez, Airín D; Bertone-Johnson, Elizabeth; Whitehill, Jennifer M. (2025). Associations Between Evolving Cannabis Policies and Cannabis-Related School Discipline Among Secondary School Students in Massachusetts, 2005-2019.. American journal of preventive medicine, 70(4), 108129. https://doi.org/10.1016/j.amepre.2025.108129