What a JAMA study of 346 Oregon psilocybin clients found

Who was studied

The study, led by researchers at Oregon Health & Science University and called the Open Psychedelic Evaluation Nexus (OPEN), followed people who received psilocybin services at 24 of Oregon's 26 actively licensed service centers, supervised by 83 licensed facilitators.¹ Clients enrolled from November 2024 to March 2026 and were followed through June 2026. Of the 346 participants, 312 (90.2%) completed the 3-month survey.¹

Participants listed several reasons for seeking services. In the corrected article, 237 (68.5%) said they wanted to improve or change themselves, 223 (64.5%) wanted to treat mental health symptoms and 178 (51.4%) wanted to process trauma.¹

What it found

• Serious reactions: 4 of 346 participants (1.2%) had serious behavioral adverse reactions, and there were no serious medical adverse reactions. All 4 were new to psychedelics and had sought services for mental health symptoms.¹
• Reported harm: 7 of 312 (2.3%) agreed their experience had been harmful at 3 months.¹
• Reported benefit: at 1 month, 296 of 321 (92.2%) said they had benefited.¹
• Symptoms: the share of participants reporting moderate-to-severe depression symptoms fell from 42.2% at the start to 16.5% at 3 months (relative risk 0.40; 95% CI 0.32 to 0.50). For anxiety it fell from 45.1% to 13.2% (relative risk 0.29), and for PTSD symptoms from 48.0% to 16.8% (relative risk 0.35).¹

Facilitators reported only 1 of the 4 serious reactions. The authors say Oregon's mandatory reporting, which covers events within 3 days of services, may undercount harms, and they urge states to track clients for months afterward.¹

What it can't tell you

The authors list the limits themselves. With no comparison group, the study can't show that psilocybin caused the changes. Participants were about 5% of the people using Oregon's services in that period, so they may not be typical. Baseline symptoms were relatively low, and participants' psychiatric diagnoses weren't known.¹ The group was mostly White, college-educated and well-off: 300 of 346 identified as White, 262 (76.6%) had at least a bachelor's degree, and 89 (29.0% of those who answered) reported household income above $200,000. The authors say this resembled Oregon's overall client population, but whether the results apply to people with lower incomes or less education, or from historically marginalized communities, remains to be determined.¹

Two corrections and a date mismatch

The article's own record says it was published August 19, 2026, and the journal's correction notice uses the same date.¹³ PubMed's citation lists August 3, 2026 instead, though its record was created August 19.² We use August 19.

The journal corrected the article on September 8, 2026 to fix a mislabeled questionnaire title. On October 16, 2026 it corrected a coding error that misclassified participants' reasons for seeking services, what the notice calls "a small number of participants with miscategorized 'other' race", and a count of lifetime psilocybin use that was 2 too high.¹³ The figures above come from the corrected version. Some percentages in PubMed's abstract differ slightly from the article's tables (86.7% versus 89.0% White, both for 300 people), so we give counts.¹²

What it means if you're in Nevada

The study describes the Oregon program that Nevadans can legally travel to; nothing like it exists here. It doesn't report where participants lived, so it can't say how many came from Nevada.¹ Oregon says a client may be found ineligible if they're having thoughts of harming themselves or others, have taken lithium within 30 days, or have ever been diagnosed with active psychosis.⁴ The authors suggest that being new to psychedelics, existing mental health conditions and higher doses may raise the risk of a serious reaction.¹

Oregon only allows psilocybin to be bought and taken at a licensed service center, and it can't be taken off-site.⁴ Psilocybin is a Schedule I drug in Nevada, so bringing any back would be illegal.⁵ See legal psilocybin nearest Las Vegas and psilocybin therapy and trials for Las Vegas residents. If someone is struggling after a psychedelic experience, our help page lists crisis and support lines.

Updated November 2, 2026: added the October 16 correction and the publication date note.