UNM researchers to study the use of psilocybin in group therapy treatment for PTSD

Amid recent widespread scholarly interest in the potential of psilocybin and other psychedelics to treat depression, post-traumatic stress disorder (PTSD), addiction and other maladies, most of the research to date has focused on therapeutic interventions offered to individuals.

Now, University of New Mexico School of Medicine researchers are launching a study in which group therapy participants will receive psilocybin – sometimes known as “magic mushrooms” – as part of their PTSD treatment. The Group Psilocybin-Assisted Therapy (GPAT) study has begun recruiting veterans and first responders with PTSD as participants and will expand recruitment to women survivors of sexual violence at the end of 2026.

The peer-to-peer interaction in group therapy has been shown to be effective in the treatment of substance use disorder and other conditions, said Lawrence Leeman, MD, MPH, a professor in the Department of Family & Community Medicine who also serves as medical director for UNM’s Milagro Program.

“When you start looking at certain conditions, such as substance use or PTSD, they all tend to relate to trauma, which is developed in relation to others,” he said. “And so, there’s a lot of reason to suspect that working in groups can be better for both of those.”

The GPAT study is aligned with the New Mexico Therapeutic Psilocybin Program in its focus on access and equity, as well as the use of state-regulated whole psilocybin mushrooms rather than a synthesized version, Leeman said. Each group will participate in two sessions in which they receive chocolates containing 20 mg or 30 mg of psilocybin, along with both group and individual therapy sessions

The group meetings will be overseen by two licensed professionals, such as a therapist or physician, and two trained peer facilitators who have shared similar experiences with the study participants, he said.

“The rationale behind including peers is that social position can be challenging in any kind of therapy,” Leeman said. “If you simply had a group of licensed therapists – for example, PhDs or MDs – there might be some effect on the connection based on these social positions.”

Psilocybin has long been used recreationally for its psychedelic properties, and there is evidence it was taken for ceremonial purposes in some Mesoamerican cultures. But a growing body of evidence suggests that it can alleviate emotional pain for people experiencing the effects of trauma by inducing a state of neuroplasticity that enables them to reframe their experiences.

In 2025 the New Mexico Legislature passed the Medical Psilocybin Act, which will eventually permit the use of psilocybin to treat qualified medical conditions, such as treatment-resistant major depression, PTSD, substance use disorders and end-of-life care. Leeman, who is helping to develop the state guidelines for the medical use of psilocybin, said the FDA-approved GPAT study is designed to assess the effectiveness and safety of the treatment and was developed with input from community groups.

“The potential of doing it this way is to have a therapy that’s not only more effective, but it is less expensive,” he said. “Especially when you’re taking it to the point where you’re starting to look at using state equity funds for doing this, that becomes important.”

Many previous studies of psilocybin “cherry pick” their results by recruiting participants with a particular diagnosis, like substance use disorder, but excluding those with confounding issues, like PTSD or depression, Leeman said. By recruiting first responders, veterans and sexual assault survivors, many of whom have multiple diagnoses, the GPAT study aims for more realistic results.

“Our study is designed to be more pragmatic,” he said. “Hopefully, we’ll get more robust results from being able to demonstrate that it’s a real-world environment that you’re selecting participants from.”