NEW YORK (Reuters Health) – Researchers
aren’t sure why, but in the 23 U.S. states where medical marijuana has
been legalized, deaths from opioid overdoses have decreased by almost 25
percent, according to a new analysis.
“Most of the discussion on medical marijuana has been about its
effect on individuals in terms of reducing pain or other symptoms,”
said lead author Dr. Marcus Bachhuber in an email to Reuters Health.
“The unique contribution of our study is the finding that medical
marijuana laws and policies may have a broader impact on public
California, Oregon and Washington first legalized medical marijuana
before 1999, with 10 more following suit between then and 2010, the
time period of the analysis. Another 10 states and Washington, D.C.
adopted similar laws since 2010.
For the study, Bachhuber, of the Philadelphia Veterans Affairs
Medical Center and the University of Pennsylvania, and his
colleagues used state-level death certificate data for all 50 states
between 1999 and 2010.
In states with a medical marijuana law, overdose deaths from opioids
like morphine, oxycodone and heroin decreased by an average of 20
percent after one year, 25 percent by two years and up to 33 percent
by years five and six compared to what would have been expected,
according to results in JAMA Internal Medicine.
Meanwhile, opioid overdose deaths across the country increased
dramatically, from 4,030 in 1999 to 16,651 in 2010, according to the
Centers for Disease Control and Prevention (CDC). Three of every
four of those deaths involved prescription pain medications.
Of those who die from prescription opioid overdoses, 60 percent have
a legitimate prescription from a single doctor, the CDC also
Medical marijuana, where legal, is most often approved for treating
pain conditions, making it an option in addition to or instead of
prescription painkillers, Bachhuber and his coauthors wrote.
In Colorado, where recreational growth, possession and consumption
of pot has been legal since 2012 and a buzzing industry for the
first half of 2014, use among teens seems not to have increased (see
Reuters story of July 29, 2014 here: http://reut.rs/1o040NI).
Medical marijuana laws seem to be linked with higher rates of
marijuana use among adults, Bachhuber said, but results are mixed
But the full scope of risks, and benefits, of medical marijuana is
still unknown, he said.
“I think medical providers struggle in figuring out what conditions
medical marijuana could be used for, who would benefit from it, how
effective it is and who might have side effects; some doctors would
even say there is no scientifically proven, valid, medical use of
marijuana,” Bachhuber said. “More studies about the risks and
benefits of medical marijuana are needed to help guide us in
Marie J. Hayes of the University of Maine in Orno co-wrote an
accompanying commentary in the journal.
“Generally healthcare providers feel very strongly that medical
marijuana may not be the way to go,” she told Reuters Health. “There
is the risk of smoke, the worry about whether that is carcinogenic
but people so far haven’t been able to prove that.”
There may be a risk that legal medical marijuana will make the drug
more accessible for kids and smoking may impair driving or carry
other risks, she said.
“But we’re already developing Oxycontin and Vicodin and teens are
getting their hands on it,” she said.
If legalizing medical marijuana does help tackle the problem of
painkiller deaths, that will be very significant, she said.
“Because opioid mortality is such a tremendously significant health
crisis now, we have to do something and figure out what’s going on,”
The efforts states currently make to combat these deaths, like
prescription monitoring programs, have been relatively ineffectual,
“Everything we’re doing is having no effect, except for in the
states that have implemented medical marijuana laws,” Hayes said.
People who overdose on opioids likely became addicted to it and are
also battling other psychological problems, she said. Marijuana,
which is not itself without risks, is arguably less addictive and
almost impossible to overdose on compared to opioids, Hayes said.
Adults consuming marijuana don’t show up in the emergency room with
an overdose, she said. “But,” she added, “we don’t put it in Rite
Aid because we’re confused by it as a society.”