Study Finds Psilocybin Can Reduce Depression for Five Years
A recent study suggests that psilocybin, the key active compound in psychedelic mushrooms, may help alleviate depression for as long as five years following just one dose. This finding was shared at the Psychedelic Science 2025 Conference held in Denver on June 18, focusing on individuals diagnosed with clinical depression, or Major Depressive Disorder (MDD). Some of these patients had participated in an earlier psilocybin study back in 2020.
Alan Davis, who is a co-author at Ohio State’s Center for Psychedelic Drug Research and Education, mentioned that a significant number of participants reported reduced symptoms of depression lasting up to five years after the treatment.
Doug Drysdale, CEO of the Canadian pharmaceutical company Cybin, expressed optimism regarding these results, even though he wasn’t directly involved in the research.
Past research has hinted at psilocybin’s potential as an antidepressant, paving the way for a randomized clinical trial. In a 2020 trial published in Jama Psychiatry, 24 patients diagnosed with MDD took part. In this trial, half the group received psilocybin initially, while the other half was treated eight weeks later, with both groups receiving 11 hours of psychotherapy.
One month post-treatment, 17 participants felt relief from their symptoms, with 14 reporting complete remission. The researchers noted that psilocybin therapy’s effectiveness, whether from a single dose or multiple doses, is a significant advantage over conventional antidepressants that require daily use.
Interestingly, this new study examined the long-term effects of the initial trial on 21 participants, revealing that 67% still experienced remission from their depression five years later. There was also a notable decrease in anxiety and an improvement in daily functioning. However, a caveat remains—Davis pointed out that this study might not adequately reflect the natural changes that can influence depression over five years.
Some of the patients who experienced a return of depression still noted lasting positive changes in their attitudes and pursuits that mattered to them. Drysdale remarked that while the results are very encouraging, further rigorous research is necessary before drawing definitive conclusions.
Experts recognize that various factors, including psychotherapy sessions and other medications, may also contribute to the long-term benefits reported by participants. The researchers emphasized caution, noting that the study’s sample may not encapsulate the broader depression-affected population.
Beyond MDD, psilocybin has been explored as a treatment for issues like postnatal depression, which impacts a significant number of new mothers. A 2022 study indicated that psilocybin could help enhance connections for these mothers, potentially improving mood and mother-infant interaction.
Considerations and Cautions
As research on psychedelics progresses, safety in administration is crucial. Ryan Moss, chief science officer at Filament Health, highlighted the necessity of conducting psychedelic treatments in controlled environments. He noted that while potential exists, there are risks, such as anxiety or delusions, associated with psychedelic experiences.
Experts recommend that the therapeutic use of psychedelics should always be managed by professionals to mitigate risks. They have identified the importance of careful monitoring during trials to prevent adverse events.
In conclusion, while there’s excitement about psilocybin and its potential mental health benefits, thorough and controlled studies are essential to understand its implications fully. The path forward appears promising, but researchers emphasize the need for caution and continued investigation.
