In recent years with the legalization of recreational cannabis among several states across the nation, there has been a need to quantify the public health impact of recreational cannabis legalization (RCL). More specifically in the young adult population, young adults are more sensitive to some of the negative effects of heavy cannabis use. In the United States turning 21 increase one’s access to alcohol and cannabis legally and socially. This study examines the differences in cannabis use among populations before and after RCL. The study hypothesized that states with RCL would predict relative increases in cannabis use outcomes among young adults.  

           This study used restricted-access NSDUH data collected yearly starting in 2008 to 2019. This data set represents all 50 states, and confidentially and maximized accuracy were ensured throughout the entire process. During the study, state of the resident identifiers was matched with RCL date. The participants self-reported with binary outcomes of cannabis use, frequent cannabis use, frequent alcohol use, and binge drinking, based on month, and past year. Roughly half of the population surveyed were the ages 21-23 years old and half were currently enrolled in a university. There was a substantial overlap being that 81% of those enrolled in college were 18-20 years of age. 21% reported use of cannabis in the past month and 11% past year. Past month frequent cannabis users were 9%, frequent alcohol use was 4%, and binge drinking was 37%.  

           It was estimated that past-month cannabis use increased from 21% in the study years before RCL in the participants’ state to 25%. Thus, this study supported the increase in young adults’ cannabis use. The study also suggested that the increase after RCL is driven more by those using cannabis. Another thing the study found was that following RCL an increase in cannabis use was only found in young adults who were not in college. Those ages 21-23 and not enrolled in college showed a relative increase in cannabis use. 

Takeaway: This study showed that young adults ages 21-23 and not enrolled in college are most likely to show an increased use of cannabis from recreational cannabis legalization.  

David C.R. Kerr, Natalie S. Levy, Harold Bae, Anne E. Boustead, Silvia S. Martins, Cannabis and Alcohol Use by U.S. Young Adults, 2008-2019: Changes in Prevalence after Recreational Cannabis Legalization, American Journal of Preventive Medicine, 2023