Medical marijuana laws do not reduce US opioid overdose deaths says study

A new study refutes the idea that the use of medical marijuana can help reduce deaths caused by opioid overdoses. Researchers from Stanford University’s School of Medicine replicated the analysis conducted in a 2014 study by researchers from the University of Pennsylvania. That study linked the medical use of marijuana to a 24.8% reduction in opioid-related deaths from 1999 to 2010 in states that had legalised the use of marijuana for medical reasons. The authors had speculated that patients might be using marijuana instead of painkillers, but they cautioned against drawing any conclusions from the data collected.

Despite the caution expressed in that study, several states hit by the opioid crisis passed medical marijuana laws hoping the laws would reduce opioid-related deaths. But when the researchers from Stanford analysed opioid death data from 1999 to 2017, they found the reverse. During the 19-year period, there was a 22.7% increase in opioid-related deaths in states that had passed medical marijuana laws.

The researchers published their findings on 10 June in the Proceedings of the National Academy of Sciences. They concluded that their findings show medical marijuana laws don’t seem to impact the rate of deaths from opioid overdoses and that, since only 2.5% of the US population uses medical marijuana, the number was too small to cause a large-scale impact.

Lead researcher, Chelsea Shover, noted it was unlikely that medical marijuana laws had a positive impact until 2014, and then had a negative impact after that. Most likely, the apparent beneficial link in the first study was a coincidence.