CBD as a cure‐all? The impacts of state‐level legalization of prescription cannabidiol (CBD) on opioid prescriptions

We investigate the impacts of state legalization of products containing cannabidiol (CBD), a non‐psychoactive alternative to marijuana, on opioid prescribing rates. Research suggests that legalized medical marijuana may reduce opioid prescriptions, though no empirical link between CBD and opioids has been ascertained. Using county‐level prescribing rates between 2010 and 2019, as well as state‐level morphine milligram equivalent (MME) consumption of 8 common opioids, we estimate that state adoption of limited access cannabis product (CBD) laws leads to no change in opioid prescribing rates. Using supply‐side access measures for access to CBD through legal and open dispensaries, we find that the ability to purchase CBD legally leads to 6.6% to 8.1% fewer opioid prescriptions at pre‐legalization means, which suggests that access to CBD products is essential when evaluating the impacts of legalization; synthetic control model estimates suggest that legal and open dispensaries reduce opioid prescribing rates by nearly 3.5% 2 years post‐legalization. We also find that mandating CBD be purchased with an ID or through a patient registry offsets most potential benefits of CBD legalization. Our results provide the first empirical evidence that: (i) state legalization of prescription CBD alone does not reduce opioid usage; (ii) regulations limiting purchasing, such as ID laws, negate nearly all of the benefits of demand‐side legalization; and (iii) supply‐side access, either via interstate purchasing or legal and open dispensaries, are vital in using pain‐management substances to fully combat the opioid epidemic.