Words Can Be Deceiving: A Review of Variation Among Legally Effective Medical Marijuana Laws in the United States.

When voters in two US states approved the recreational use of marijuana in 2012, public debates for how best to promote and protect public health and safety started drawing implications from states' medical marijuana laws. However, many of the discussions were simplified to the notion that states either have a medical marijuana law or do not; little reference was made to the fact that legal provisions differ across states. This study seeks to clarify the characteristics of medical marijuana laws in place since 1990 that are most relevant to consumers/patients and categorizes those aspects most likely to affect the prevalence of use, and consequently the intensity of public health and welfare effects. Evidence shows treating medical marijuana laws as homogeneous across states is misleading and does not reflect the reality of medical marijuana lawmaking. This variation likely has implications for use and health outcomes, and thus states' public health.