The primary psychoactive compound in magic mushrooms, psilocybin, may significantly reduce depression for up to five years after a single dose, a recent study suggests.

The findings, shared on June 18 at the Psychedelic Science 2025 conference in Denver, revisited patients previously diagnosed with clinical depression — also termed major depressive disorder (MDD) — who took part in a psilocybin treatment study in 2020.

“The majority of participants in our trial reported a reduction in the intensity of depression symptoms or noted changes in how they experienced depression, with these effects lasting for up to five years after the trial,” study co-author Alan Davis, who is also the director of the Center for Psychedelic Drug Research and Education at The Ohio State University, shared with Fox News Digital.

Doug Drysdale, CEO of the Canadian pharmaceutical company Cybin in Toronto, Ontario, told Fox News Digital that the outcome speaks to the “exciting” potential of psilocybin and other psychedelic-based treatments in treating MDD and other mental health conditions.

“The results of the study are certainly very encouraging,” said Drysdale, who was not involved in the study.

Earlier studies pointed toward the possibility of psilocybin as a potential antidepressant, prompting researchers to conduct the first-ever randomized clinical trial.

The initial 2020 trial, published in JAMA Psychiatry, included 24 patients with major depressive disorder.

Half received psilocybin at the beginning of the trial, and the other half received the treatment eight weeks later. 

Each patient also underwent 11 hours of psychotherapy.

One month after treatment, 17 patients reported experiencing symptom relief.

Fourteen of those reported full remission from depression, according to the published study.

“The effectiveness of psilocybin therapy after a single or only a few administrations represents another substantial advantage over commonly used antidepressants that require daily administration,” the researchers wrote.

The new study aimed to explore the longer-term effects of this treatment on 21 of the original trial participants.

Sixty-seven percent reported being in remission from depression five years after treatment, and they also had less anxiety and easier daily functioning.

For those whose depression came back, many still reported lasting benefits in their attitudes, perspectives and ability to pursue things that were meaningful to them, Davis told Fox News Digital.

“Certainly, more controlled and rigorous study is required, but at least anecdotally, these findings are very interesting, and I am cautiously optimistic about the potential for extended efficacy provided by these types of treatments,” Drysdale added.

Other factors may have also played a role in the participants’ long-term mental health benefits, such as psychotherapy sessions or other antidepressants, experts agreed.

“The study doesn’t account for naturalistic changes that could have affected their depression in the five years since the main trial, and the sample is not representative of the population of people suffering with depression,” Davis told Fox News Digital.

Psilocybin has also been explored as a potential treatment for post-partum depression (PPD), which affects as many as one in seven new mothers.

A 2022 study outlined the potential role of psychedelics in PPD cases, finding that psilocybin has been shown to catalyze a sense of “reconnection” in new mothers.

“This effect in PPD, by fostering a sense of ‘reconnection’ for the mother, may allow for improved mood and maternal sensitivity toward the infant, which can positively impact maternal role gratification and the mother-infant relationship,” the researchers stated.

In February, Cleveland Clinic reported on an upcoming study that explores single-dosing psilocybin as a way to treat PPD.

The trial, now in its second phase, focuses on RE104, a proprietary drug similar to psilocybin. 

Study participants will undergo multiple physical and mental health tests.

Potential risks and limitations

Ryan Moss, chief science officer at Filament Health, a clinical-stage natural psychedelic drug development company in Canada, has emphasized the importance of administering psychedelics in a safe setting when treating mental health conditions.

“Psychedelic experiences can sometimes feature anxiety, hallucinations and paranoia,” Moss previously told Fox News Digital. 

“Some patients using traditional psychedelics have reported experiencing adverse cardiovascular events during clinical trials.”

To mitigate these risks, Moss recommended clinical trial participants receive thorough preparation and monitoring by trained professionals during sessions. 

Dr. Marc Siegel, clinical professor of medicine at NYU Langone Medical Center and Fox News’ senior medical analyst, previously interviewed two of the country’s top researchers on psychedelics: Dr. Rachel Yehuda, founder and director of the Center for Psychedelic Psychotherapy and Trauma Research at Mt. Sinai in New York, and Dr. Charles Marmar, director of the PTSD research program at NYU Langone.

“They agree there is therapeutic potential if very carefully studied under very strict medical guidance, but there is a huge downside in terms of unregulated recreational uses,” Siegel told Fox News Digital at the time.

“Both doctors see likely therapeutic value to psychedelics if carefully managed by medical experts,” Siegel added.

Melissa Rudy and Angelica Stabile, both of Fox News Digital, contributed reporting.