OHSU Multisite Study Finds Mental Health Gains and Low Serious Harms From Oregon’s Regulated Psilocybin Services

Overview

• The multisite cohort of 346 adults who used licensed psilocybin services at 24 Oregon centers was reported in JAMA Network Open on Aug. 19–20, 2026 with roughly 90% of participants completing three-month follow-up.
• Participants reported clear benefit: 91.5% said they benefited at one month and 64.9% called the session among their 10 most meaningful life experiences, with group-level drops in moderate-to-severe depression, anxiety and PTSD at three months.
• Serious physical-health events were not reported and serious adverse reactions were uncommon, though four first-time users had behavioral reactions that required medical attention and seven reported the experience as harmful at three months.
• The authors warned psilocybin is not appropriate for people with psychosis, bipolar disorder, or pregnancy and noted the study sample may be healthier than clinical-trial groups, which limits how broadly the results can be applied.
• Policy and research follow-ups are already under way: more than 20,000 people have used licensed Oregon services to date, a $3.3 million federal grant will fund substance-use research, and the monitoring platform is expanding to Colorado as access barriers from cost and county opt-outs remain unresolved.