Recreational Cannabis Legalization Leads to Higher Use in Some Demographics

The U.S. is seeing an increased use of cannabis resulting from its legalization for recreational purposes, according to a study conducted at Columbia University Mailman School of Public Health. The findings showed that passage of the laws led to a rise in the odds of past-year and past-month cannabis use (those that used cannabis at least once in the past year or in the past month) among individuals of Hispanic, Other and non-Hispanic white race/ethnicity compared to the period prior to enacting laws for recreational use. However, most importantly, as of 2017, legalization did not lead to more frequent use or cannabis use disorder among these groups. And no changes in use were observed among non-Hispanic Black people or among individuals aged 12-20 of all racial/ethnic groups, for whom cannabis use remains illegal.

The findings, which focused on states that had already legalized medical cannabis, are published in JAMA Network Open .

“Until this study, little was known about changes in cannabis use outcomes by race or ethnicity following passage of recreational cannabis laws among states that already had passed medical cannabis use laws,” said Silvia Martins, MD, PhD, associate professor of epidemiology at Columbia Mailman School, and first author. “Furthermore, as one of the stated goals of cannabis legalization is to combat racial inequalities in cannabis legislation enforcement, it is critical to examine patterns of use in the context of persistent racial and ethnic disparities in cannabis arrests and incarceration.”

By January 2021, 15 states and Washington, D.C. had fully legalized cannabis use for adults over 21, and an additional 21 states had legalized medical cannabis.

Using data from the 2008–2017 National Surveys of Drug Use and Health, between September 2019 and March 2020 for those 12 years of age and older, the researchers studied approximately 70,000 individuals annually or a total of 838,600 respondents, of whom 65 percent self-identified as Non-Hispanic White, 12 percent as Non-Hispanic Black, 16 percent as Hispanic, and 8 percent as Other Race or Ethnicity.

The prevalence of past-year cannabis use increased after the enactment of recreational cannabis laws among individuals who self-identified as Hispanic (12 to 15 percent), Other (15 to 19 percent), and Non-Hispanic White (17 to 19 percent). Past-month cannabis use also increased after the enactment of recreational cannabis laws for the three racial-ethnic groups. However, among non-Hispanic Black individuals, no changes were seen in the prevalence of any cannabis outcome after enactment of recreational use legislation.

“Enactment of recreational cannabis laws is often framed as an issue of social and racial justice,” noted Martins, who is also director of Columbia’s Substance Use Epidemiology Unit. “Historically, regulation and criminalization of substances in the U.S. have targeted substances associated with marginalized groups.”

For example, the data show that in 2018 the lifetime prevalence of cannabis use was lower for non-Hispanic Black adults compared to non-Hispanic white adults (45 and 54 percent, respectively). However, Black adults were 3.64 times more likely to be arrested for cannabis possession. Even in states that legalized cannabis before 2018, Black people were still 1.72 times more likely to be arrested for cannabis possession, indicating that racist and discriminatory targeting of people of color persists despite changing policies.

In the future, monitoring unintended and intended consequences that may be attributable to the passage of recreational policies should be a priority to ensure that the enactment of recreational cannabis laws truly effects greater racial and ethnic equity and adheres to anti-racist goals, observes Martins.

“This study contributes to our understanding of racial and ethnic changes in cannabis use that occur after the legalization of adult marijuana use in the U.S.,” said Martins. “But longer-term studies will be necessary across all racial and ethnic groups to observe whether or not the prevalence of daily cannabis use and cannabis use disorder remain unchanged. It is far too early to see increases in the odds of cannabis use disorder; this transition among users can occur only several years after regular cannabis use.”

Co-authors include Luis Segura, Natalie Levy, Pia Mauro, Christine Mauro, and Morgan Philbin, Columbia Mailman School of Public Health; and Deborah Hasin, Columbia Mailman School of Public Health and Columbia University Irving Medical Center.

The study was supported by the U.S. National Institutes of Health, National Institute on Drug Abuse (DA037866, DA048860, DA045224, DA039804).