The federal National Institute on Drug Abuse, long perceived as blocking research on marijuana’s medical uses, may be cracking its doors open a bit.
The institute is funding a University of California at Davis study on whether vaporized cannabis can treat neuropathic pain from spinal-cord injuries, and has agreed to supply marijuana for one at the University of Arizona Medical College on its use to treat post-traumatic stress disorder among veterans.
Still, although the number of NIDA-funded studies involving cannabis has increased dramatically over last decade, from 22 for $6 million in 2003 to 69 for $30.2 million in 2012, the overwhelming majority are concerned with it as a drug of abuse, such as studying its possible links to schizophrenia or treatments for “cannabis dependence.” Only a handful are exploring its potential medical uses.
“It’s a very slow trickle,” says Kris Hermes of Americans for Safe Access, a medical-marijuana advocacy group. NIDA’s Web site, revised this year, lists “potential therapeutic uses of THC and other cannabinoids in treatment of pain, HIV, and addiction” as one of the eight categories of marijuana research it funds. As of January 31, it was funding 28 such studies, including one that explores whether the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) could be used to treat arthritis pain in guinea pigs and whether THC inhibits the spread of an HIV-like virus in apes.
In March, the institute announced a $117,000 grant to Temple University School of Medicine in Philadelphia to explore whether cannabidiol (CBD) alone is a safer and more effective painkiller than THC or a THC-CBD combination in mice. It’s also funding a Yale University study on whether CBD could be used as an antipsychotic drug.
Nine of those 28, however, involve the use of cannabinoids, such as large doses of synthetic THC (dronabinol, aka Marinol), to treat “cannabis dependence” and “cannabis withdrawal.” NIDA has also funded studies on whether nicotine patches, the anti-seizure drug gabapentin, and various antidepressants can serve a similar purpose.
“We’re the National Agency on Drug Abuse, not the National Agency for Drug Abuse.”
NIDA says that the marijuana plant is “therapeutically less promising than medications derived from cannabinoids.” Its reasons for this stance are the drug’s psychoactive effects, the dangers of addiction and smoking, and because “it is also difficult to standardize dosages of a highly variable herb delivered in cigarettes or food.”
Dr. Sue Sisley, researcher on the proposed Arizona PTSD study, disagrees vehemently. The 60-odd cannabinoids in marijuana, she says, work synergistically, in an “entourage effect” too complex to be replicated by a single-molecule drug—so to help real-life patients, you have to study the effects of the whole plant.
Medical-cannabis research depends on the federal government for two reasons. First, because marijuana is a plant that can’t be patented, drug companies won’t pay for clinical trials. (The main exception is Sativex, a cannabis-extract spray legal in Canada but not yet approved in the U.S.) Second, NIDA’s farm at the University of Mississippi is the only legal source of it for research. (Dr. Lyle Craker of the University of Massachusetts spent 12 years trying to get permission to grow his own supply.) Since 1999, the agency says, it has approved 16 of 18 applications for cannabis from independently funded studies.
“NIDA brags that they’re responsible for 80 percent of the research that goes on worldwide,” says Paul Armentano of the National Organization for the Reform of Marijuana Laws. But with the federal government treating marijuana users as criminals and denying that it has a valid medical use, he adds, “it’s hard to imagine” that it “would fund research that undermines its policy.”
Dr. Donald Abrams, a pioneering AIDS researcher who now heads the oncology department at San Francisco General Hospital, says that in the mid-1990s, when he first sought to study whether smoking marijuana could prevent AIDS wasting syndrome, NIDA’s then-director told him, “We’re the National Agency on Drug Abuse, not the National Agency for Drug Abuse.” He was able to gain funding for a 1997 study on whether it was safe for AIDS patients taking protease inhibitors to use cannabis or dronabinol, and found that neither affected their viral load nor the rate at which their bodies absorbed the anti-HIV medication.
NIDA, he says, funds research that is “looking at safety and not efficacy.”
On the other hand, he says, the quality of its product has improved. The Mississippi farm now supplies loose, fresh cannabis of up to 6.8 percent THC instead of freeze-dried, stem-contaminated ganja in pre-rolled cigarettes with only 3.5 percent THC.
Beginning in 2000, California funded 12-odd studies through the Center for Medicinal Cannabis Research, based at UC San Diego. Dr. Abrams was able to use that to do a 2007 study that found marijuana was significantly more effective than a placebo in reducing HIV-related neuropathic pain, and another that found that vaporization was as effective as smoking for getting THC into patients’ blood, but with far lower levels of carbon monoxide. The center also funded research on using smoked cannabis to reduce spasticity in multiple-sclerosis patients and on the use of cannabinoids to treat migraine headaches.
The center’s funding, however, was not renewed by the state legislature in 2012.
Dr. Sisley’s PTSD study illustrates the barriers. The Multidisciplinary Association for Psychedelic Studies, which is trying to raise funds for the project, submitted its proposal in November 2010. The Food and Drug Administration approved it six months later, but NIDA and the Public Health Service rejected their request for a supply in September 2011. The University of Arizona’s institutional review board approved a revised proposal in October 2012, and the PHS approved the request for cannabis this March 14. All that was left was for the Drug Enforcement Administration to approve her storage procedures. But NIDA just informed her and MAPS that they couldn’t provide some of the cannabis requested, because the high-CBD, low-THC strain was out of stock and that "they don't have the mix of 5-6% THC, 5-6 percent CBD they said they had," said Brad Burge of MAPS.
“The NIDA monopoly needs to be ended,” Sisley says.
This spring, notes Armentano, several state legislatures, including those in Kentucky, Tennessee, and Alabama, passed measures authorizing and funding CBD trials at their state universities. Whether NIDA approves a cannabis supply for those projects, he says, will be “telling” about whether the agency is “shifting from an antagonist” to being “willing to play a collaborative role.”