I'm just reading an article that is discussing the study:
A study
published Monday in PNAS contradicts that widely cited paper, raising new questions about whether and how
medical marijuana can affect the opioid crisis.
The 2014 study found that between 1999 and 2010, states with medical cannabis laws had a nearly 25% lower average rate of opioid overdose deaths than states without such laws. Much has changed since 2010 — 34 states have now legalized medical marijuana and the number of opioid overdose deaths was six times higher in 2017 than it was in 1999 — so Stanford University researchers decided to replicate the original study and expand its analysis to include seven more years of data.
So their point is that there are more opioid deaths in 2017 than 1999... and they're positioning this as an 'in spite-of' increased cannabis legalization.
First of all, of course there are more opioid deaths in 2017 than 1999:
I'm just going to let this graph speak for itself. I don't know if it was the study's purpose to study the affects of cannabis on opioid deaths, or if it was just a data point of a more sensible study that the media is running with, but if it was the purpose of the study it seems like a huge waste of time in light of the evidence we already had.