The Drug Enforcement Administration has ruled marijuana should remain classified as a dangerous drug like heroin because studies have not confirmed its medicinal value, but the agency may itself be to blame for the lack of evidence.

The DEA denied a 9-year-old petition to initiate proceedings to reschedule marijuana in late June, claiming that "marijuana has a high potential for abuse, has no accepted medical use in the United States, and lacks an acceptable level of safety for use even under medical supervision." The decision (PDF) was announced Friday.

The petition was filed by The Coalition for Rescheduling Cannabis and sought to have marijuana removed from schedule I of the federal Controlled Substances Act and rescheduled in schedule III, IV or V. Currently, the DEA classifies marijuana as a schedule I drug: the most restrictive classification reserved for street drugs like heroin with no real medicinal value.

"Although this superficially looks like a defeat for the medical marijuana community," said Joe Elford, Americans for Safe Access Chief Counsel and lead counsel in the recent lawsuit. "It simply maintains the status quo."

"More importantly, however, we have foiled the government's strategy of delay and we can now go head-to-head on the merits, that marijuana really does have therapeutic value," Elford continued.

The use of medical marijuana has been legalized in 16 states and the District of Columbia. But, according to the DEA, marijuana cannot be considered to have medicinal value because there is a lack of scientific studies assessing its safety and efficacy as a medicine, and the scientific evidence is not widely available. The agency also noted there are no U.S. Food and Drug Administration (FDA)-approved marijuana products at present.

But marijuana's status as a schedule I substance has prevent clinical studies from being conducted. The DEA has repeatedly denied Dr. Lyle E. Craker's application for the production of medical marijuana, blocking the University of Massachusetts professor from conducting scientific studies that would seek to determine the drug’s medical benefits.

In response, the American Civil Liberties Union called on the DEA in March to grant research permits for the production of medical cannabis. They also flatly stated that the reason cannabis medicines have not yet cleared the Food and Drug Administration (FDA) is because of the DEA's pernicious politics and tight monopoly on the granting of production licenses.

"The federal government’s official policy is that marijuana has no medical benefit," they noted. "But the government is unwilling to put its policy to the test of science: instead, the government exercises monopoly control over the nation’s supply of marijuana that may be used for scientific purposes, by allowing an agency whose mission is to explore the consequences of the abuse of marijuana—the National Institute on Drug Abuse (NIDA)—to determine what research may go forward regarding marijuana’s beneficial medical uses. The result is that [...] marijuana alone out of all potential medicines is subject to a special and obstructive process that places politics over science."

In 2009, the American Medical Association, the largest physician's organization in the U.S., adopted a resolution calling on the DEA to reclassify marijuana to faciliate research on marijuana-based medicines.

"Results of short term controlled trials indicate that smoked cannabis reduces neuropathic pain, improves appetite and caloric intake especially in patients with reduced muscle mass, and may relieve spasticity and pain in patients with multiple sclerosis," the AMA's resolution (PDF) reads.

"The future of cannabinoid-based medicine lies in the rapidly evolving field of botanical drug substance development, as well as the design of molecules that target various aspects of the endocannabinoid system. To the extent that rescheduling marijuana out of Schedule I will benefit this effort, such a move can be supported."

With prior reporting by Stephen C. Webster