Tulsi Gabbard on health: what the evidence says · JRE #1295
SUBJECT: HEALTH
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
There has been a correlation in states that have legalized either medical use or adult use of cannabis, a direct correlation in a reduction of opioid addiction, as well as opioid-related deaths.
What the evidence says 01 / RECORD
A widely publicized 2014 study (Bachhuber et al., JAMA Internal Medicine) found that, from 1999 to 2010, states with medical cannabis laws had a 24.8% lower mean annual opioid analgesic overdose mortality rate than states without such laws. However, a 2019 replication and extension by Shover et al. (Stanford, published in PNAS) using data through 2017 found the association reversed direction, becoming a 22.7% increase in opioid overdose mortality in medical-cannabis states. The same study found no statistically significant association between adult-use (recreational) cannabis laws and opioid overdose mortality. The authors concluded the original correlation was likely spurious rather than causal, noting medical cannabis users represent only a small fraction of the population, insufficient to plausibly drive state-level mortality trends. Current evidence therefore does not support a direct, durable correlation between cannabis legalization and reduced opioid deaths; the relationship that gave rise to the claim has not held up with more years of data.