Kenneth Glad
Psychedelic-assisted treatment is being tested for some of the hardest-to-treat cases in mental health care. The evidence so far suggests real interest, but also a need for restraint.
A small study has added a sober note to the debate over psilocybin, the psychedelic compound being studied for depression.
The Lancet Regional Health – Europe writes that psychiatrists at the University Hospital of Psychiatry Zurich reviewed 19 patients with treatment-resistant depression who received psilocybin under Switzerland’s limited medical-use exemption.
Study tempers expectations
Treatment-resistant depression usually means a patient has not improved after standard treatments. That can leave doctors with fewer reliable options and patients facing repeated disappointment.
In the Zurich cohort, depression scores fell. But only about one-third of patients responded, meaning symptoms dropped substantially, while about one-fifth reached remission, meaning symptoms became minimal or much less severe.
The study was small, so its findings cannot settle the wider debate. Still, it offers a glimpse of how psilocybin may perform outside tightly controlled trials.
Rotem Petranker, Ph.D., director of the Canadian Centre for Psychedelic Science, told Drug Discovery Trends that the result still matters:
“All the participants in this study had treatment-resistant depression, meaning nothing works. Imagine any disorder where nothing works, where every treatment we can give you is palliative, and then something works, even if it doesn’t work for everyone. I think that’s pretty cool.”
Larger trials show restraint
Early psilocybin studies helped create major public and commercial excitement around psychedelic medicine. Later research has not erased that interest, but it has made the claims harder to simplify.
Drug Discovery Trends reports that Compass Pathways, a company developing psilocybin-based therapy, said that two Phase 3 trials met their main goals, though the difference from control groups was limited. The company plans to seek approval by the end of 2026.
The field is also carrying lessons from MDMA-assisted therapy for post-traumatic stress disorder. According to Drug Discovery Trends, the U.S. Food and Drug Administration rejected Lykos Therapeutics’ application in 2024 and asked for another Phase 3 trial.
“It was clear to everyone but the Multidisciplinary Association for Psychedelic Studies (MAPS) that the FDA wouldn’t approve it, because their submission didn’t fit the requirements,” Petranker told Drug Discovery Trends.
That decision highlighted a recurring challenge in psychedelic research. Patients can often tell whether they received an active drug, which can make expectation difficult to separate from the medicine’s direct effect.
A narrower path ahead
Recent analyses in JAMA Network Open and JAMA Psychiatry found that psilocybin and psychedelic-assisted therapy may not clearly beat established antidepressant approaches once trial design and patient expectations are weighed.
Petranker has urged the field to slow down and test claims more carefully.
“What we need now is rigorous, slow science,” he said.
For now, psilocybin looks less like a sweeping turning point and more like a treatment that may have value in particular cases.
The question is no longer whether the compound can produce improvement for some patients, but how often, how durably and under what clinical conditions.
Sources: Drug Discovery Trends, The Lancet Regional Health – Europe, JAMA Network Open, JAMA Psychiatry
