Study reveals changing patterns in cannabis use
A new study led by Boston College School of Social Work Professor Summer Sherburne Hawkins found that recreational cannabis legalization in the United States is driving increases in cannabis use among adults with historically lower consumption, as opposed to increasing use among those who already consumed cannabis.
The research, titled “The Impact of Recreational Cannabis Legalization on Cannabis Use in US Adults from 2016-2023: A Quasi-experimental Study” and published in the American Journal of Preventive Medicine, contributes evidence that cannabis use—the most frequently consumed illicit drug in the U.S.—is spreading to new populations.
Despite a December 2025 executive order, cannabis remains a Schedule I controlled substance under U.S. federal law, but as of January, 24 states—including Massachusetts—and the District of Columbia have legalized recreational cannabis for adults 21 and older, with most allowing commercial sales.
Summer Sherburne Hawkins (Caitlin Cunningham)
“Analyses of state-representative data from 2016 onwards indicated that recreational cannabis legalization is contributing to rising levels of adult cannabis use by increasing the proportions of adults using cannabis,” said Hawkins, who also serves as associate director of BC’s Global Public Health and the Common Good program. “Demographic groups with lower levels of cannabis use —adults who were older, female, white, or college-educated—have increased their likelihood of use the most following legalization.”
Escalating evidence on the physical and mental health risks of cannabis, particularly for frequent use and consumption among younger people, has important ramifications in the face of rising levels of cannabis use, noted the study. Research has identified numerous potential impacts of cannabis use, including dependency, cognitive impairment, and adverse effects on cardiovascular and respiratory systems. At the same time, the proportion of adults who perceive there to be no risks from cannabis use has risen.
“The increased risk of cannabis use disorder with earlier entry and frequent use is concerning, as are the plummeting public perceptions of the adverse consequences of cannabis use,” said Hawkins.
According to recent research published in the journal Addiction and a survey conducted by the U.S. Department of Health and Human Services, cannabis use has been rising for decades among American adults. In 2023, 25.2 percent of individuals aged 18-25 and 15 percent of adults over 26 reported using cannabis in the past month. Cannabis use is more prevalent across certain demographic groups, particularly adults who are younger, male, identify as white or Black, have lower education and income levels, and comprise higher-risk groups, including adults who report depressive symptoms or engage in polysubstance use.
To examine whether cannabis legalization was driving these trends, the Hawkins-led study evaluated the impact of recreational cannabis legalization on adult cannabis use across the adult population overall and by demographic and higher-risk strata among participants in the 2016-2023 Behavioral Risk Factor Surveillance System (BRFSS).
The BRFSS is an annual, state-representative telephone survey of over 400,000 adults aged 18 years and older, administered in all 50 states and the District of Columbia by state health departments and the Centers for Disease Control and Prevention.
The final study sample included 859,600 respondents from 38 states, the only states that included cannabis questions from 2016 through 2023. Three states legalized recreational cannabis prior to 2016 and an additional 17 states by 2023. Cannabis use averaged 11.9 percent across the study period and varied across states, ranging from seven percent in Nebraska to 22.4 percent in Oregon. Cannabis use increased by about one percentage point in response to legalization, a nearly 10 percent relative increase from 2016 levels. Furthermore, adults aged 60 years and older, female, white, or college-educated were the most responsive to legalization, with one to two percentage point increases in use, translating to 15 to 37 percent relative increases compared to 2016 levels of use.
“As recreational cannabis legalization continues to expand across the U.S., monitoring how patterns of cannabis use change in response to legalization is essential for understanding the short- and long-term implications across populations,” Hawkins said. “Our findings highlight that recreational cannabis legalization should be coupled with broad public health outreach and awareness, including health education campaigns and initiatives to increase health literacy around cannabis.”
Given the study’s results, recent legislation in Massachusetts warrants monitoring, noted the researchers. The state agency overseeing cannabis regulation voted in December to permit marijuana lounges, establishing new social consumption licenses that will allow business owners to launch cannabis cafes and host marijuana-infused events. These regulations make Massachusetts the first state in New England to permit these establishments.