Researchers say CDC data show that deaths caused by prescription opioid overdoses rose in every state from 1999 to 2010. However the yearly rate of these deaths in states with medical marijuana laws, was about 25 percent lower, on average, than the rate in states without these laws.
The study's lead author, who's from the Philadelphia V.A. Medical Center says these findings suggest that the availability of medical marijuana for pain treatment might help to reduce the growing number of overdose deaths attributed to prescription pain pills.
"In absolute terms, states with a medical marijuana law had about 1,700 fewer opioid painkiller overdose deaths in 2010 than would be expected based on trends before the laws were passed," says the study's lead author, Marcus Bachhuber, MD, of the Philadelphia Veterans Affairs Medical Center and the University of Pennsylvania.
Bachhuber cautions that the exact mechanism underlying these results is unclear. It could be due, he says, to people with chronic pain choosing alternative treatments, or medical marijuana laws might also change the way people abuse or misuse prescription pain medications, or something else entirely.