Abstract
PURPOSE: Since October 2022, a total of 21 states have enacted both medical-use and adult-use cannabis legalization, each with their own unique set of laws, regulations, implementation, structures, and enforcement ("policies"). Unlike adult-use programs, medical-use programs often represent a safer and affordable option for patients with diverse needs; however, current evidence suggests that medical-use program activity decreases after implementation of adult-use retail. The current study compares medical patient registration data and medical- and adult-use retail data from 3 distinct medical- and adult-use states (Colorado, Massachusetts, and Oregon) in the time after adult-use retail implementation in each state. METHODS: To investigate changes in medical cannabis programs with simultaneous adult-use legalization, correlation and linear regression analyses were used to assess outcome measures: (1) medical-use retail sales; (2) adult-use retail sales; and (3) number of registered medical patients in all fiscal quarters after adult-use retail sales were implemented in each state to September 2022. FINDINGS: Adult-use cannabis sales increased significantly over time in all 3 states. However, both medical-use sales and number of medical patients registered in the states increased only in Massachusetts. IMPLICATIONS: Results indicate that states' preexisting medical-use programs may undergo critical changes after adult-use cannabis legalization is enacted and implemented. Key policy and program differences, such as regulatory differences in the implementation of adult-use retail sales, may have differential impacts on medical-use programs. For continued patient access, it is critical that future research assess the differences within and between states' medical-use and adult-use programs that permit sustainability of medical-use programs alongside adult-use legalization and implementation.