Almost two-thirds of U.S. patients prescribed medical marijuana are using it as a treatment for chronic pain, according to a new study.

Published in Health Affairs last month, the study’s authors argue their findings are in line with the large number of Americans who suffer chronic pain and the strong scientific evidence that marijuana is an effective pain treatment.

Since 1996, thirty-three U.S. states and the District of Colombia have legalized marijuana for medical use. Patients receiving medical marijuana require a doctor to certify they have a condition that qualifies for treatment. Patients can then be issued with a license in states where medical marijuana is legal.

For the new study, researchers analysed data from state registries tracking the number of patients using medical marijuana and the conditions it was prescribed to treat. Twenty states and the District of Colombia had registries tracking patients using medical marijuana, while 15 states held data on the conditions that qualified patients for the drug.

65% of patients use marijuana for chronic pain

The researchers found that 65 percent of medical marijuana patients used it to treat chronic pain. The other most common reasons patients used medical marijuana were for multiple sclerosis, nausea and vomiting induced by chemotherapy, and post-traumatic stress disorder.

The study team also looked at how often medical uses of marijuana are evidence-based. Based on a 2017 report by the National Academies of Science that assessed the scientific evidence supporting the use of marijuana to treat specific conditions, they found uses had strong backing 86 percent of the time.

Most patients use medical marijuana for evidence-backed conditions

“The vast majority of conditions for which people use cannabis have substantial or conclusive evidence of cannabis being an effective treatment,” said lead study author Kevin Boehnke of the University of Michigan in Ann Arbor.

“However, that doesn’t mean that it’s going to necessarily be easy for them to figure out how best to use cannabis or cannabinoids to treat their conditions,” Boehnke said.

Boehnke explains that unlike traditional prescription drugs, there are no clinical guidelines for medical marijuana. This is largely because even though many states have legalized medical marijuana, the federal government still classifies it as a “schedule 1” substance with no medical use and a high potential for abuse.

“Medical cannabis patients are placed in a position where they typically have no choice but to experiment to find their optimal dosing regimen,” Boehnke added. “Safety is definitely a concern, especially when smoking or taking high doses of THC.”

The study authors conclude that a nationwide patient registry would make it easier to understand how patients are using medical marijuana and whether it’s safe or effective for these conditions.

Dr. Kevin Hill, a researcher at Harvard Medical School in Boston, was not involved in the study but agrees with the authors that there are still many problems with how medical marijuana is used in day-to-day medical practice.

“Many physicians in specialty cannabis clinics will give certifications to anyone who will pay for it, and the level of follow-up care is often poor,” Hill said.

“One way we can change this is to improve the education that healthcare professionals receive on medical cannabis so that they will feel more comfortable certifying patients when appropriate and be more likely to offer useful guidance to patients on what type of cannabis to obtain, how to dose it, and what side effects to look out for,” Hill added.

“Right now, ‘budtenders’ often play a more important role in medical cannabis than doctors do – and that needs to change.”

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