Researchers repeated an analysis that sparked excitement years ago.
The previous work linked medical marijuana laws to slower than expected increases in state prescription opioid death rates from 1999 to 2010.
The original authors speculated patients might be substituting marijuana for painkillers, but they warned against drawing conclusions.
Still, states ravaged by painkiller overdose deaths began to rethink marijuana, leading several to legalize pot for medical use.
When the new researchers included data through 2017, they found the reverse: States passing medical marijuana laws saw a 23% higher than expected rate of deaths involving prescription…