Assessing the Effects of Medical Marijuana Laws on Marijuana and Alcohol Use: The Devil is in the Details

Abstract

This paper sheds light on previous inconsistencies identified in the literature regarding the relationship between medical marijuana laws (MML) and recreational marijuana use by closely examining the importance of policy dimensions (registration requirements, home cultivation, dispensaries) and the timing of them. Using data from our own legal analysis of state MMLs, we evaluate which features are associated with adult and youth recreational use by linking these policy variables to data from the National Longitudinal Survey of Youth (NLSY97), the Youth Risk Behavior Survey (YRBS) and the Treatment Episodes Data System (TEDS). Our analyses control for state and year fixed effects, using within state policy changes over time to estimate the effect on changes in our outcome variables using a difference-indifferences approach. We find that while simple dichotomous indicators are generally not associated with marijuana use, specific dimensions of MMLs, namely home cultivation and legal dispensaries, are positively associated with marijuana use in each data set. Moreover, these same dimensions are tied to binge drinking and fatal alcohol automobile accidents as well. The findings have important implications for states considering legalization of marijuana, as regulating access to and promotion of dispensaries may be key for reducing the harms associated with these policies.

The effect of medical marijuana laws on adolescent and adult use of marijuana, alcohol, and other substances

“…First, although all MMLs specify a list of conditions that are eligible for medical marijuana, 4 most MMLs include in the list a generic term "chronic pain", rather than specific diseases causing the pain (e.g., neuropathy, fibromyalgia, rheumatoid arthritis, etc.) (Pacula et al, 2013). The interpretation of "chronic pain" can go far beyond the original legislative intent, analogous to the practice of off-label prescribing of other medications.…”

“…The variation in specific states laws implemented during different periods may help reconcile the mixed findings from the previous studies. To explore this potential heterogeneity, a recent study by Pacula et al (2013) uses the same data sets as Anderson et al (2011Anderson et al ( , 2012 but replaces a single dichotomous MML indicator with a set of indicators that represent key provisions of MMLs. Although none of the estimates using a dichotomous MML indicator are significant, the MMLs that include a provision requiring patient registry/renewal are found to lower the marijuana use rates and marijuana-related treatment admissions.…”

“…The spillover effect may arise from four dimensions of the existing MMLs that create a de facto legalized environment for marijuana use in the general population (Pacula et al, 2013). First, although all MMLs specify a list of conditions that are eligible for medical marijuana, 4 most MMLs include in the list a generic term "chronic pain", rather than specific diseases causing the pain (e.g., neuropathy, fibromyalgia, rheumatoid arthritis, etc.)…”

Data on cannabis use now that legalization is gaining momentum

“…Since our goals for the paper [1] were to highlight new cannabis supply regimes and to initiate a discussion about evaluating these changes, we could not have asked for a better set of commentaries [2][3][4]. Each essay makes a strong contribution to the conversation about how to learn from jurisdictions experimenting with alternatives to cannabis prohibition.…”

The rise of marijuana and the fall of cocaine in the United States: for better, for worse?

“…Uncertainties also pertain to potential causes of increasing use of marijuana in the United States, as both Canada and the United States have seen a proliferation of medical marijuana programs but have seen divergent patterns of cannabis use [12,13]. Recent evidence concerning the impact of such programs on the prevalence of marijuana use also appears to be mixed [9,14,15].…”