States that have enacted laws allowing for the medicinal use of marijuana have lower annual rates of drug overdose death than do states without such laws, according to a study.
The link between such laws and lower rates of overdose deaths remains unclear, according to an analysis published online Monday in JAMA Internal Medicine
, but the findings showed states with medical marijuana laws in place had a nearly 25% lower average yearly opioid overdose death rate compared with states without those laws.
“We can't know the exact mechanism behind the findings,” said study author Dr. Marcus Bachhuber, an internal medicine fellow at the Philadelphia Veterans Affairs Medical Center. “We think it may be due to people with chronic pain using medical marijuana instead of opioid prescription painkillers, but it may also be that medical marijuana laws shift behavior in other ways.”
The study found that as a result of medical marijuana
laws, there were more than 1,700 fewer deaths in those states than expected in 2010.
The findings were calculated through an examination of state mortality rates from opioid drug overdose between the years 1999 and 2010. Deaths rates were cross referenced with states that had enacted medical marijuana laws in the years prior to 2010. Three states, California, Oregon and Washington, had laws in place prior to 1999, while 10 states enacted laws during the period studied. Nine more states implemented medical marijuana laws after 2010 and were not counted within the study period. New Jersey was counted because its law went into effect in late 2010.
Despite the findings, the number of opioid drug overdose deaths has increased in states with and without medical marijuana laws. Government estimates have shown a stark increase in prescription painkiller use and overdose mortality over the past decade across the country. Figures from the Centers for Disease Control and Prevention
indicate opioid pain relievers were involved in 14,800 deaths in 2008, accounting for 40% of all drug overdose deaths.
In an effort to reverse the trend, the U.S. Drug Enforcement Administration recently announced plans to tighten restriction on hydrocodone and Vicodin by giving them the same types of drug classification as such highly addictive prescription drugs as oxycodone and morphine, making them less accessible for nonmedical use.
“Almost 7 million Americans abuse controlled-substance prescription medications, including opioid painkillers, resulting in more deaths from prescription drug overdoses than auto accidents,” DEA Administrator Michele Leonhart said in a statement
last week. The DEA action “recognizes that these products are some of the most addictive and potentially dangerous prescription medications available.” Follow Steven Ross Johnson on Twitter: @MHsjohnson