“In short, our findings that legally protected and operating medical marijuana dispensaries reduce opioid-related harms suggests that some individuals may be substituting towards marijuana, reducing the quantity of opioids they consume or forgoing initiation of opiates altogether,” the study concludes. “Marijuana is a far less addictive substance than opioids and the potential for overdosing is nearly zero.”
While previous research has shown that medical marijuana laws are associated with lower opioid overdose rates, the new analysis distinguished between states where medical cannabis is simply legal and states that actually allow streamlined patient access to marijuana through active dispensaries.
“Because legal protection of retail dispensaries does not mean dispensaries are operational, we construct our policy measure to identify the state/year in which dispensaries are both legally protected and open for business,” researchers from the RAND Corporation, the National Bureau of Economic Research and the University of California, Irvine wrote. “Dispensaries – retail outlets that sell marijuana to qualified patients – contribute to the decline in opioid overdose death rates.”
To be more specific:
“Using data from just the early period of these laws 1999–2010, dispensaries reduce opioid mortality rates by about 40%, above and beyond the reduction from marijuana laws alone. The total effect is estimated to be even larger. When we consider the full time period (1999–2013), the estimates imply that dispensaries reduce opioid mortality rates by about 20% while the main effect of having a law is relatively small in magnitude, implying declines of about 5%, and not statistically distinguishable from zero. Importantly, together – a marijuana law with a legal, operational dispensary provision – the estimates imply a statistically significant (at the 5% level) decline in overdose death rates of about 25%.”
“It is clear that operational dispensaries are critical,” the study, published online over the weekend by the Journal of Health Economics, concluded. “This evidence is consistent with the need for a clear and legal supply chain for medical marijuana policy to have an effect.”
Going a step further, the study, which was funded by the National Institute on Drug Abuse, found that examining data from after 2010, “a period when states began opening more tightly regulated medical marijuana retail systems,” apparently in response to federal enforcement guidance, weakens the effect.
“The effect of medical marijuana policies on opioid related harm diminishes over time, particularly after 2010, which might be due to the regulatory tightening of medical marijuana dispensaries, the major marijuana policy feature behind the reduced harm in the earlier period,” the data suggests.
Nonetheless, the researchers concluded that “our results suggest a potential overlooked positive effect of medical marijuana laws that support meaningful retail sales.”