Frustrating those wishing to study its medical potential, marijuana will remain a Schedule I substance, the most tightly regulated class of drugs in the United States. The announcement today by the Drug Enforcement Administration (DEA) keeps marijuana in the same class as heroin, LSD, and other potentially dangerous or highly addictive drugs and comes as a disappointment to U.S. researchers who have argued that looser restrictions are needed to facilitate studies on whether cannabis can treat conditions ranging from chronic pain to brain tumors to childhood epilepsy.
There was a glimmer of good news for those scientists in the DEA announcement, though. The administration will amend a policy that had restricted them to a single source of marijuana for research studies, a federally-funded farm at the University of Mississippi.
DEA’s decision not to reschedule marijuana presents a Catch-22. By ruling that there is not enough evidence of “currently accepted medical use”—a key distinction between the highly restrictive Schedule I classification and the less restrictive Schedule II—the administration essentially makes it harder to gather such evidence.
“They’re setting a standard that can’t be met,” says David Bradford, a health economist at the University of Georgia, Athens. “That level of proof is never going to be forthcoming in the current environment because it requires doing a really extensive clinical trial series, and given that a pharmaceutical company can’t patent whole plant marijuana, it’s in no company’s interest to do that.”
Schedule I status presents obstacles for clinical researchers because of restrictions on how the drugs must be stored and handled, Bradford says. Perhaps more significant, that listing may evoke skittishness at funding agencies and on the institutional review boards that must sign off on research involving human subjects.
Bradford sees DEA’s move to allow additional growers to provide marijuana for federally sanctioned research as a positive step, if only a modest one. That’s because it should allow researchers to investigate a wider variety of strains, including ones closer to what people are actually using in states where medical marijuana is legal.
The DEA decision came in response to two petitions to reschedule marijuana: one filed in 2009 by a psychiatric nurse practitioner in Albuquerque, New Mexico, who uses cannabis to treat posttraumatic stress disorder, the other filed in 2011 by two state governors, Lincoln Chafee of Rhode Island and Christine Gregoire of Washington. The administration drew on a review of the scientific and medical research literature by the Food and Drug Administration (FDA) in consultation with the National Institute on Drug Abuse.
In a letter to the petitioners, DEA acting administrator Chuck Rosenberg acknowledged that marijuana is not as dangerous as many drugs listed as Schedule I. However, Rosenberg said, based on the standards used for drug approval by FDA, marijuana does not meet the criteria for rescheduling. “It does not have a currently accepted medical use in treatment in the United States, there is a lack of accepted safety for its use under medical supervision, and it has a high potential for abuse,” Rosenberg wrote. “If the scientific understanding about marijuana changes—and it could change—then the decision could change.”
Meanwhile, medical marijuana is now legal in 25 states, plus the District of Columbia. According to one estimate, more than 1.2 million people have acquired medical marijuana cards in those states.