Some U.S. military veterans received unpleasant news last week when they tried enrolling in a clinical trial conducted by the Department of Psychiatry and Behavioral Science at Johns Hopkins University. Upon calling a widely circulated hotline number intended to connect former servicemembers to researchers conducting a study on the efficacy of smoked cannabis as a treatment for post-traumatic stress disorder, they learned the study wasn't happening. Not at Hopkins, anyway.

"If you are calling about the PTSD study, please know we are no longer participating in that study," the voicemail greeting said as of Monday morning. While the message has been playing since at least last week, neither Johns Hopkins University nor the psychiatry department had formally announced withdrawing from the study as of yesterday.

That's why Sean Kiernan, president of the Warriors for Weed Project, sent a letter to Johns Hopkins University Ron President on Monday demanding that the university publicly explain why it was no longer participating in the study, which is sponsored by the Multidisciplinary Association for Psychedelic Studies (MAPS).

"We're upset with Hopkins," Kiernan told me by phone today. "Something is going on there."

A clinical trial measuring the efficacy of smoked marijuana as a treatment for PTSD has been in the works since 2014, when the Department of Health and Human Services approved MAPS' request to purchase research cannabis from the National Institutes on Drug Abuse. NIDA holds a monopoly on legally growing and providing marijuana for research purposes, and a clinical trial is the first step in having whole-plant marijuana moved from Schedule I of the Controlled Substances Act to Schedule II, where it can be legally prescribed for therapeutic purposes. (Currently, doctors may recommend marijuana under state laws, but they may not prescribe it under federal law.)

The trial was slated to take place at both the University of Arizona and Johns Hopkins, but was briefly delayed when the University of Arizona fired researcher Sue Sisley, allegedly to avoid the wrath of Arizona lawmakers who opposed her work on medical marijuana. In 2016, Sisley announced she would continue her portion of the trial at the Scottsdale Research Institute. Sisley, along with Johns Hopkins professor Ryan Vandrey, would study whether various doses of smoked marijuana could help reduce the symptoms of treatment-resistant PTSD, using a $2 million grant MAPS received from the Colorado Department of Public Health and Environment.

While Sisley's work will continue, Vandrey, of the Johns Hopkins Behavioral Pharmacology Research Unit, confirmed to me in an email on Monday that his team "has withdrawn its participation in the MAPS study." He referred me to a university spokesperson for additional information. On Tuesday, a university spokesperson released the following statement:

"It is Johns Hopkins' mission to conduct high quality scientific research and save lives. Johns Hopkins elected to withdraw from the MAPS study of cannabis in veterans with PTSD prior to any participant enrollment because our goals for this study weren't in alignment. Johns Hopkins remains dedicated to helping military veterans, finding improved treatments for PTSD, and conducting innovative research to enhance our understanding of both the risks and benefits of cannabis/cannabinoids."

"Johns Hopkins wanted to remain focused on clinical research, and MAPS wanted to focus on the science as well as on the policy issues surrounding the science related to the NIDA monopoly on marijuana for research," Brad Burge, communications director for MAPS, wrote in an email. "We still have an exceptionally strong research team, including the researchers at the University of Pennsylvania and the University of Colorado, as well as the Scottsdale Research Institute in Phoenix. We think the study will still succeed without Johns Hopkins' involvement, that we'll be able to enroll all the participants we need at the Phoenix site, and that the study will still have sufficient diversity of participant population."

NIDA, a frequent funder of research projects at Hopkins' Department of Psychiatry and Behavioral Science, came under scrutiny earlier this month when PBS published a story revealing that the NIDA-run facility at the University of Mississippi had provided low-quality cannabis to researchers working on the MAPS study. "It didn't resemble cannabis. It didn't smell like cannabis," Sisley told PBS. She also revealed that the samples were infected with mold, and that the potency was not what researchers requested. No one from Johns Hopkins, which has also received cannabis from NIDA, is mentioned in the PBS story.

Kiernan suspects that Hopkins' relationship with NIDA and the recent kerfuffle over the agency's mishandling of marijuana samples played a role in the university's decision to withdraw from the trial. But he's waiting for a full explanation.

"We had a vet call in to Hopkins who wanted to participate in this study," Kiernan says. "He called me, upset, after he got that voice message. What I want Hopkins to tell me is, Why did you back out of this study with a voicemail message? Do you know what veterans are going through?"