Barriers to marijuana research keep scientists in the dark on health effects
The powdery green substance Dr. Sue Sisley uses for medical marijuana research bears little resemblance to the plush flower buds people buy at dispensaries or on the street.
It comes from the National Center for Natural Products Research at the University of Mississippi, the only source of pharmaceutical-grade marijuana and marijuana-derived materials available through the National Institute for Drug Abuse's Drug Supply Program.
"It’s not like I can go to another dispensary and buy it; I can’t," said Sisely of the Arizona-based Scottsdale Research Institute, who has studied the use of marijuana to treat post-traumatic stress disorder, chronic pain and opioid addiction. "That's my only legal drug supply.
"It’s like a green talcum powder with very little aroma, and visible stems, sticks, seeds, lots of extraneous plant material," she added. "It’s moldy ... (and) it doesn’t come close to representing potencies in the real world."
Limited access to government-approved marijuana is one of several regulatory barriers to marijuana research. Because cannabis is a Schedule 1 drug — the designation reserved for heroin, LSD and other substances considered dangerous and of no medical value — such studies require approval from the federal Drug Enforcement Agency and other agencies as well in some cases.
Limited federal funding is available for cannabis efficacy studies, those that explore marijuana's potential as a medicine. Most federally funded marijuana studies focus on the dangers of the drug.
"This is one of the big, big difficulties in this space," said Kevin Boehnke, a post-doctoral research fellow at the University of Michigan's Department of Anesthesiology who has studied the impact of legalization in other states.
"While there are a whole host of researchers that would love to do that kind of work, cannabis is a Schedule 1 substance. That means that to be able to do that study in a controlled way, like a randomized controlled trial, people would need to get DEA approval.
"They would likely need to get funding from the government and they would need to go through the FDA (federal Food and Drug Administration), as well as need to go through the National Institute of Drug Abuse supply chain to get cannabis products."
Researchers may also face institutional resistance from universities or hospitals reluctant to get involved in cannabis research.
Sisely lost her job as an assistant professor of clinical psychiatry at the University of Arizona in July 2014, shortly after the National Institute on Drug Abuse approved her proposal to study cannabis treatment for PTSD. The university didn't say why her contract was not renewed, according to media reports at that time.
Interest in marijuana research has expanded as more and more states have approved pot for medical or recreational use, said Charles Pollack, director of the Lambert Center for the Study of Medicinal Cannabis and Hemp at Thomas Jefferson University in Philadelphia.
"Universities are understandably hesitant because of the Class 1 status," he said. "But maybe 10 or 15 years ago there was more of a stigma."