Psilocybin, the primary psychoactive component in magic mushrooms, has been shown to relieve depression for at least five years following a single dose, according to new research.
This study was presented on June 18th at the Psychedelic Science 2025 Conference in Denver, focusing on individuals with major depressive disorder (MDD), commonly known as clinical depression. This serious mood disorder leads to prolonged feelings of sadness and a diminished interest in activities previously enjoyed. Conventional treatments for MDD generally consist of psychotherapy and medications, including Selective Serotonin Reuptake Inhibitors, both of which can take considerable time to manifest benefits.
After preliminary studies indicated the potential of psilocybin as an antidepressant, the research team initiated their first randomized clinical trial to investigate the use of psychedelics for severe depression. The trial involved 24 participants, where one half received psilocybin at the outset, while the other half received the same dose eight weeks later—the “waitlist” group. Each participant also underwent 11 hours of psychotherapy.
Even within this brief timeframe, “depression was significantly diminished in the immediate treatment group compared to that of the waitlist,” stated the study’s co-authors. Alan Davis, director of Ohio State’s Center for Psychedelic Drug Research and Education, shared with Live Science.
Upon completion of the four-week study, psilocybin was found to be four times more effective than conventional antidepressants based on previous research findings. One month post-treatment, 17 patients reported a reduction in symptoms, including 14 who achieved full remission. Furthermore, participants responded to psilocybin significantly faster than typical antidepressant treatments.
But do these benefits of psilocybin last?
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Long-term research on psilocybin for depression has been scarce, noted Dr. Charles Raison, a Professor of Human Ecology and Psychiatry at the University of Wisconsin Madison, who was not involved in the study.
“Conducting these studies is challenging since participants may drop out,” Raison remarked to Live Science via email. “This complicates understanding whether the enduring benefits stem from psychedelics, psychotherapy, or a combination thereof.”
The researchers contacted former participants several years after the trial to invite them for a follow-up study. Twenty-one individuals participated, and clinical assessments were made to evaluate changes in depression levels from the time of initial treatment to present.
Participants also filled out self-reported online questionnaires documenting their interactions with clinicians, daily functioning, anxiety levels, and overall mental health. The researchers assumed that the three individuals who declined to participate in the follow-up, as well as three others who did not complete the survey, were not in remission.
Notably, the researchers discovered that 67% of participants who battled depression six months prior remained in remission after a single psychedelic therapy session. These individuals consistently reported reduced anxiety and improved daily functioning. Overall, two-thirds of responding patients noted lasting positive transformations in their mindset, emotional well-being, and relationships.
“We are thrilled about the profound impact of these interventions beyond just alleviating depression,” Davis expressed.
Many participants indicated that post-treatment, they engaged in self-reflection and therapeutic practices to better understand themselves and handle life’s challenges. Davis theorizes that future studies should compare the relative efficacy of psilocybin versus psychotherapy in fostering deeper therapeutic insights and reducing depression.
“The primary caution regarding this study lies in its small sample size, as previous trials indicated stronger antidepressant effects compared to larger multi-site studies that followed,” Raison pointed out, referring to multi-site clinical trials featuring 233 participants, where 37% of 79 individuals who took a single dose of 25 mg of psilocybin, along with psychotherapy, found themselves in remission from major depression.
Despite these trials demonstrating a weaker impact from antidepressants, they do support the idea that psilocybin is a viable treatment for depression, Davis noted, eager to observe the long-term effects of multi-site trial data five years post-treatment.
Source: www.livescience.com