Massachusetts High School Surveys Found No Increase in Teen Cannabis Use After Adult-Use Legalization

A 2023 study of high school students in Massachusetts found no statistically significant increase in past-30-day cannabis use after the state legalized cannabis for adults. The study, published in Clinical Therapeutics, compared survey responses collected in 2016, before legalization, with responses collected in 2018, after legalization but before licensed recreational cannabis stores opened.

The researchers analyzed two waves of surveys from students at two high schools in eastern Massachusetts. Reported past-30-day use was broadly similar across the two periods: 19% of female students and 27% of male students reported recent use in 2016, compared with 20% and 28%, respectively, in 2018. The small differences were not statistically significant.

Massachusetts voters approved adult-use legalization in November 2016, but the first licensed recreational sales did not begin until November 2018. That timing is important: the study examined changes in the social and legal environment after legalization, not the longer-term effects of a fully established retail market. The state’s Cannabis Control Commission records document the sequence of legalization and retail sales.

Although students’ own reported use did not rise meaningfully, their perceptions of cannabis use among people close to them did change. The share who believed a parent used cannabis increased from 18% in 2016 to 24% in 2018. Students who perceived cannabis use by a parent, sibling or best friend were more likely to report using cannabis themselves. Perceived best-friend use showed the strongest association, with an adjusted odds ratio of 17.2 in the study’s statistical analysis.

Those findings indicate a relationship, not proof that a friend or family member caused an adolescent to use cannabis. Shared environments, social influences and other underlying factors may all contribute. The researchers also cautioned that the results came from only one Massachusetts school district and should be tested in larger, more representative populations.

Faith English, the study’s lead author, and senior author Jennifer Whitehill said the research was designed to examine specific roles within adolescents’ social networks rather than treating family and peers as a single category. That distinction may help public-health programs identify young people who could benefit from prevention or early intervention.

The Massachusetts results are consistent with the broader conclusion that adult-use legalization does not automatically produce an immediate increase in adolescent cannabis use, though findings vary by study, population and time period. National monitoring remains important because youth use patterns, perceived risk and methods of consumption can change over time. The federally funded Monitoring the Future survey tracks these trends among U.S. students, while the Centers for Disease Control and Prevention’s guidance on cannabis and teens summarizes the health concerns associated with adolescent use.