Medical marijuana: good evidence for some diseases, weak for others

Reuters 23 June 2015
Moderate- or high-quality evidence supports the use of marijuana for some medical conditions, but not for others, according to a fresh review of past research.

After reviewing 80 randomized trials that included nearly 6,500 people, researchers found moderate support for using marijuana to treat chronic pain and muscle spasms and involuntary movements.

The evidence wasn’t as strong to support marijuana’s use for nausea and vomiting due to chemotherapy, sleep disorders, HIV-related weight loss and Tourette syndrome.

Also, any benefits of marijuana or cannabis use must be weighed against the risk of side effects, which include dizziness, dry mouth, nausea, sleepiness and euphoria, according to the study’s lead author.

“Individuals considering cannabinoids as a possible treatment for their symptoms should discuss the potential benefits and harms with their doctor,” said Penny Whiting of University Hospitals Bristol NHS Foundation Trust in the UK.

She also told Reuters Health by email that other reviews of medical marijuana suggest prolonged use may be tied to an increased risk of psychosis.
http://www.reuters.com/article/2015/06/23/us-marijuana-medical-evidence-idUSKBN0P31WT20150623

Scant evidence that medical pot helps many illnesses – study
Associated Press 23 June 2015
Medical marijuana has not been proven to work for many illnesses that state laws have approved it for, according to the first comprehensive analysis of research on its potential benefits.

The strongest evidence is for chronic pain and for muscle stiffness in multiple sclerosis, according to the review, which evaluated 79 studies involving more than 6,000 patients. Evidence was weak for many other conditions, including anxiety, sleep disorders, and Tourette’s syndrome and the authors recommend more research.

The analysis is among several medical marijuana articles published Tuesday in the Journal of the American Medical Association. They include a small study suggesting that many brand labels for edible marijuana products list inaccurate amounts of active ingredients. More than half of brands tested had much lower amounts than labeled, meaning users might get no effect.

Highlights from the journal:
THE ANALYSIS
The researchers pooled results from studies that tested marijuana against placebos, usual care or no treatment. That’s the most rigorous kind of research but many studies found no conclusive evidence of any benefit. Side effects were common and included dizziness, dry mouth and sleepiness. A less extensive research review in the journal found similar results.

It’s possible medical marijuana could have widespread benefits, but strong evidence from high-quality studies is lacking, authors of both articles say.
http://hosted.ap.org/dynamic/stories/U/US_MED_MEDICAL_MARIJUANA_RESEARCH_5_THINGS?SITE=AP&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2015-06-23-11-51-43