Now comes a study from Stanford University School of Medicine showing that when researchers looked at a longer period of time, states that introduced medical marijuana actually had 23 percent more deaths from opioid overdoses.
The new work appears to be a cautionary tale about inferring cause and effect — wanting research to show something it can’t because the nation is in the grip of a deathly opioid epidemic or because there is money to made by offering possible solutions. The opioid crisis, now more than two decades old, has taken more than 400,000 lives, according to government data.
“A lot of people interpreted the first study as causal because it’s congenial to their goals,” said Chelsea L. Shover, a postdoctoral fellow in psychiatry who was part of the Stanford research team. “It did not say that one is causing the other.
“I wish it were true,” she added. “I wish that passing medical cannabis [laws] would solve the opioid crisis. But the evidence doesn’t support that.”