In brief
- A follow-up of 346 individuals who used Oregon’s legal psilocybin services found sustained improvements in depression, anxiety, and post-traumatic stress symptoms three months after their session.
- 91.5% reported benefits one month after the experience, and 64.9% ranked it among the ten most significant events of their lives.
- The study, published in JAMA Network Open, recorded few harms: seven people reported some negative impact at three months, and there were no serious physical adverse events.
A team led by Todd Korthuis of Oregon Health & Science University (OHSU) has published the most extensive follow-up to date on the legal psilocybin program operating in the state since 2023. This is not a controlled clinical trial; it is an observational study conducted in real-world conditions with individuals who independently visited one of Oregon’s 24 licensed centers and agreed to complete questionnaires before their session, as well as one week, one month, and three months afterward. The results were published on August 19 in JAMA Network Open.
What was measured and how
The team recruited 346 participants between November 2024 and June 2026 via a web portal where they tracked their mood and symptoms at various intervals following a psilocybin session administered by a licensed facilitator. Retention was high: 90% of participants completed the three-month follow-up, giving the study significant statistical weight for data collected outside of a laboratory setting. Along with Colorado, Oregon is one of the few places in the world where adults can access supervised psilocybin sessions without a prior medical diagnosis—a model that prioritizes regulated access and professional support over prohibition.
The specific data
One month after the session, 91.5% of participants reported having benefited, and 64.9% classified the experience as one of the ten most significant events of their lives. At three months, moderate to severe symptoms of depression, anxiety, and post-traumatic stress had decreased notably, while well-being and life satisfaction had improved. Regarding safety, only seven people described any harm at the three-month mark, and four first-time users had behavioral adverse reactions that required prompt medical attention; no serious physical events were recorded. Korthuis summarizes the safety profile as “very similar to what we have seen with psychedelics in clinical settings.” The work was publicly funded, including a $3.3 million grant from the National Institute on Drug Abuse (NIDA) and the federal agency SAMHSA, as part of a long-term monitoring initiative called OPEN (Open Psychedelic Evaluation Nexus) that plans to expand the sample size in the coming years.
What it implies
The team itself notes the limitations of the design: without a control group or random assignment, it is impossible to isolate how much of the improvement is due to the psilocybin, the facilitator’s support, the setting of the session, or the fact that those paying out-of-pocket for this service—ranging from several hundred to several thousand dollars—tend to have better general health than the population typically found in clinical trials. Furthermore, not all Oregon counties permit licensed centers, which limits real-world access. Even with these caveats, the value of this work lies in its portrayal of how psilocybin functions when used outside the lab within a legal framework with professional support: the combination of regulated access, honest information, and harm reduction appears to sustain positive results with few incidents—a relevant finding as other territories debate whether to open similar pathways for access.
Related previous coverage: First public NHS trial supports psilocybin for resistant depression.
Source
- OHSU News. Study finds sustained benefit for people using Oregon psilocybin services. Oregon Health & Science University, August 19, 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
