An Arizona psychiatrist is tantalizingly close to federal approval for a groundbreaking study of marijuana’s potency in treating PTSD — if only the National Institute on Drug Abuse would stop stonewalling her.

Dr. Sue Sisley, an assistant professor of psychiatry at the University of Arizona College of Medicine and a psychiatrist whose practice treats mostly war veterans, wants to add evidence-based science to the ubiquitous anecdotal reports, not to mention animal research, that point to marijuana’s effectiveness at quelling symptoms of post-traumatic stress. Although plenty of vets smoke up, medical marijuana can only be prescribed to PTSD sufferers living in New Mexico — where 27 percent of those with an approved ID card suffer from PTSD, making it the state’s number one qualifying diagnosis — and nary a study has evaluated whether the illicit drug actually works.

“Plenty of the veterans I’ve treated use marijuana, only they usually buy it illegally and use it covertly,” Sisley told Danger Room. “With research, we can actually figure out which symptoms it might help with, and what an optimal dosing strategy might look like.”

With PTSD afflicting as many as 37 percent of this generation’s Iraq and Afghanistan vets, and no fail-proof treatment available, the Pentagon’s already turned an eye to unconventional research. Military docs look into everything from brain rebooting to neck injections. But they’ve yet to offer anybody a joint, and Sisley’s efforts are now at a standstill: After months of back-and-forth, federal regulators just won’t give her proposal the green light.

“At this point, I can’t help but think they simply don’t want to move forward,” she said. “Maybe they figure if they stall long enough, we’ll give up and go away.”

Sisley’s study would be triple-blind and placebo-controlled, meaning none of the researchers or veterans would know who’s getting high and who isn’t. She plans to evaluate 50 veterans, all of whom would spend 30 days marijuana-free before participation. For two two-month stretches, they’d be asked to either smoke or vaporize a maximum of 1.8 grams a day, and would be given weekly supplies of various strains of marijuana with THC levels ranging from 0 percent to 12 percent.

Of course, Sisley acknowledges that it’s a study with potential for abuse. (Cheech and Chong marathon, anyone?) That’s why participants will be given small supplies of the drug, asked to videotape each smoking session and return any leftover weed.

“If we get a chance to do this, we’re not taking liberties,” she said. “This is a carefully controlled, rigorous scientific study. We’re not sitting around trying to get these vets high.”

And already, Sisley and her sponsor, the Multidisciplinary Association for Psychedelic Studies (MAPS) — a non-profit that advocates for medical research of banned substances, and is currently sponsoring a study on ecstasy as a PTSD treatment — have made significant progress in getting the study approved. Earlier this year, the FDA okayed their research proposal, after which it was sent to a panel of five reviewers at the National Institute on Drug Abuse (NIDA) and the Public Health Service (PHS).

Marijuana is the only controlled substance whose use in research needs to be approved by the NIDA. The federal agency has a monopoly on supplies of research weed, so aspiring investigators need the NIDA’s approval before they can legally buy the stuff. But after four months of evaluation, the panelists in September rejected the proposal, citing, among other factors, Sisley’s lack of experience in treating veterans with PTSD and concerns over patients using such a substance associated with “a number of safety issues” outside a medical facility.

And in order to move forward with funding, the panelists need to reach unanimous approval. But they’re all over the map when it comes to Sisley’s study. In the rejection document, one panelist noted that researchers should only “perform the study in marijuana naive subjects.” Another advised using an “experienced population.” All that incoherence makes Rick Doblin, the executive director of MAPS, fear for Sisley’s proposal.

“They’re making absolutely contradictory statements,” he told Danger Room. “Not to mention that we’re asking for marijuana from an agency designed to prevent people from using marijuana. There’s something fundamental that just doesn’t work here.”

NIDA didn’t respond to requests for comment. But a spokesperson helpfully informed the Washington Post that “the production and distribution of marijuana for clinical research is carefully restricted under a number of federal laws and international commitments.”

Sisley might not have the health officials on her side, but she is catching the eye of some Veteran’s Affairs staff members. Several have offered to (quietly) refer patients for the study, and two VA doctors in Phoenix — Dr. Deb Gilman and Dr. Lauren Lee, both with significant experience treating PTSD — have signed on as co-investigators to help Sisley’s proposal pass NIDA muster.

“The doctors I know think this war on marijuana is awful, and they’re tired of being in the middle of it,” Sisley said. “They just want to do real research, or read real research, and not operate around all of these agendas.”

As Sisley prepares to tweak and re-submit her proposal, Doblin and MAPS are busy trying to break up NIDA’s marijuana monopoly. They’re stuck in an ongoing lawsuit with the DEA, after the agency in 2001 rejected MAPS’ proposal to build their own medical-marijuana growing facility.

And potential study participants — Sisley has heard from hundreds of interested vets — might be wise to hope the MAPS lawsuit works out before the study is okayed. Turns out, NIDA’s pot kinda sucks anyway.

“At one point, years and years ago, they were selling it to researchers for $7 a gram, which is not a bad price,” Doblin said. “But really, it’s terrible quality.”

Photo: Noah Shachtman