In recent years, a number of states have legalized medical marijuana. While marijuana may not be good for you, can it be used as a substitute for more dangerous substances such as prescription opioids and heroin? To use an analogy, perhaps marijuana is to vaping ans opioids/heroin are to smoking.
In fact, a recent paper by Powell et al. (2018) finds that this is the case:
Recent work finds that medical marijuana laws reduce the daily doses filled for opioid analgesics among Medicare Part-D and Medicaid enrollees, as well as population-wide opioidoverdose deaths. We replicate the result for opioid overdose deaths and explore the potential mechanism. The key feature of a medical marijuana law that facilitates a reduction in overdose death rates is a relatively liberal allowance for dispensaries. As states have become more stringent in their regulation of dispensaries, the protective value generally has fallen. These findings suggest that broader access to medical marijuana facilitates substitution of marijuana for powerful and addictive opioids.