Just because medical marijuana is approved to treat conditions like anxiety, sleep disorders, and Tourette's syndrome doesn't mean it actually provides any benefit. That's the takeaway from a new JAMA assessment of 79 studies involving nearly 6,500 people that found little evidence the drug helps patients, including those suffering from depression and glaucoma, the AP and LiveScience report. The strongest evidence of marijuana's positive effects came in those with chronic nerve or cancer pain. Patients who took cannabinoids like THC or CBD were 40% more likely to see at least a 30% reduction in pain compared to those using a placebo. Positive effects were also seen in those with muscle stiffness related to multiple sclerosis and in chemotherapy patients dealing with nausea and vomiting, but that's not to say that marijuana treats those conditions only or at all, adds Reuters.
Some researchers argue too little is known about marijuana's potential benefits because research is often hindered by governments against its use. The studies that do exist tend to be small and based on "low-quality scientific evidence, anecdotal reports, individual testimonials, legislative initiatives, and public opinion," the study authors say. "Imagine if other drugs were approved through a similar approach." However, the Department of Health announced yesterday that it will eliminate a federal Public Health Service review of research proposals, which could allow more privately funded medical marijuana research. Colorado has also pledged some $8 million to explore pot's potential benefits, including possible effects on veterans suffering from PTSD. "It's not a wonder drug but it certainly has some potential," a researcher says. (A drug that could top medical marijuana already exists.)