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.
- In the paper abstract, 296 of 321 (92.2%) reported benefit at one month, and 188 of 321 (58.6%) ranked it among their ten most meaningful experiences.
- 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 a cohort study of the regulated psilocybin programme 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 enrolled 346 participants between November 2024 and March 2026, with follow-up through June 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, without removing participant selection, self-report or the lack of a control group. 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
The primary abstract reports one-month benefit in 296 of 321 people (92.2%) and an experience among the ten most meaningful in 188 of 321 (58.6%). OHSU’s release gives different figures, 91.5% and 64.9%; this review uses the paper’s values and denominators rather than combining them. 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, seven of the 312 three-month respondents (2.3%) reported harm, 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.” OHSU acknowledges support from NIDA, SAMHSA, its foundation and other funding. Its release also mentions a $3.3 million grant for a future substance-use line; that announcement should not be treated as this cohort’s total budget.
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 cannot be identified as the cause of changes in this uncontrolled design. Findings describe participants and do not guarantee efficacy or safety for every person or regulatory model. JAMA published a correction on 16 October concerning baseline categories for reasons, race and prior psilocybin use. The notice does not attribute the percentage discrepancy with OHSU to that correction.
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.
