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Arizona Researcher Completes First Study Of Marijuana As PTSD Treatment

Sue Sisley
Sue Sisley
handout | contributor
Sue Sisley om 2019.

An Arizona researcher has completed the first ever clinical trial of marijuana to treat PTSD.

Researchers hope to publish the results of the three-year study soon.

Dr. Sue Sisley, a physician and the principal investigator, said there were days she thought the study may never come to fruition.

“The first seven years was just navigating all the barriers to research — all the regulatory agencies and the rejections,” Sisley said.

In 2014, Sisley gained notoriety when the University of Arizona fired her as she was preparing to launch the FDA-approved clinical trial.

She eventually relocated to the Scottsdale Research Institute where she conducted the study of how 76 veterans with Post Traumatic Stress Disorder responded to smoking whole plant marijuana.

“We don’t know what the results of the study are yet, but we hope we can curb the severity of their PTSD symptoms,” Sisley said.

Four different varieties of cannabis were given to the participants — all with different properties. Each veteran decided when and how much to smoke, although with a limit of no more than 1.8 grams a day.

“Sometimes we saw veterans that had no symptoms on a good day and they wouldn’t use any cannabis. Others would use it only at night to initiate sleep or to suppress nightmares and flashbacks,” she said.

They smoked cannabis over the course of three weeks and then were required to abstain for two consecutive weeks. Symptoms were measured using the Clinician-Administered PTSD Scale (CAPS) — considered the gold standard for measuring the severity of PTSD symptoms.

Sisley had to wade through a variety of concerns before the FDA signed off on the study design.

“The FDA was concerned about having an outpatient study, about transporting the study drug from the lab back to the home and allowing patients to adjust the dose each day to treat symptoms.” 

The study was a triple blind randomized control trial, meaning all parties — the veterans, the researchers and the independent raters — had no idea what was being administered to each participant.  

Sisley is now sifting through the results to see what they show.

“All of the data from this study, the good and the bad of cannabis, will be published,” she said. “Everything gets put into the public domain so everyone gets a chance to scrutinize it.”

The Multidisciplinary Association for Psychedelic Studies ( MAPS) funded the $2.1 million study using a grant from the Colorado Department of Public Health and Environment and with the approval of federal agencies like the Drug Enforcement Agency and the National Institute on Drug Abuse.

“We have not seen a new treatment for PTSD on the market in over 17 years,” she said. 

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Will Stone grew up with the sounds of public radio. As a senior field correspondent, he strives to tell the same kind of powerful stories that got him into the business — whether that means trudging through some distant corner of the Sonoran Desert or uncovering an unknown injustice right down the street. Since joining the KJZZ newsroom in 2015, he has covered political scandals, fights over the future of energy, and efforts to care for some of Arizona’s most vulnerable communities. His pieces have also aired on national programs like Morning Edition, All Things Considered, Here & Now and Marketplace. Before coming to KJZZ, he reported for public radio stations in Nevada and Connecticut. Stone received his degree in English literature from Haverford College, where he also wrote about the arts and culture scene in Philadelphia. After graduating, he interned at NPR West in Culver City, California, where he learned from some of the network’s veteran reporters and editors. When he doesn’t have a mic in hand, Stone enjoys climbing mountains, running through his central Phoenix neighborhood and shamelessly promoting his cat, Barry.