Landmark US Study Explores Legal Psilocybin's Impact on Addiction Recovery

A first-of-its-kind federally funded study is examining the real-world effects of legal psilocybin use in regulated settings. Oregon Health & Science University (OHSU) is leading the five-year project, backed by a $3.3 million grant from the National Institute on Drug Abuse (NIDA). The research aims to fill critical gaps in understanding how psilocybin—found in 'magic mushrooms'—affects diverse populations, particularly those struggling with substance use disorders.

The Oregon Psychedelic Evaluation Nexus (OPEN) will track over 1,600 participants for 12 months after their first psilocybin session. Researchers will assess who benefits most from the substance, which conditions it may effectively treat, and any difficult psychological reactions that arise. This work builds on recent progress in setting quality standards for psilocybin services.

Oregon remains the only US state with a fully operational, state-regulated system for legal psilocybin therapies, established under Measure 109 in 2023. Colorado is developing a similar framework, with licensed centres expected to open in 2025. No other states have implemented comparable programmes.

The study is particularly focused on substance use disorders, an area where rigorous data is scarce despite growing clinical and public interest. OHSU's involvement highlights the need for addiction medicine expertise in psychedelic research, ensuring the findings are grounded in evidence-based practice.

The initiative marks the first federally funded investigation into state-sanctioned psilocybin services. Results could shape future policies on legal access and therapeutic use. By documenting outcomes across different groups, the study may provide clearer guidance on safety, efficacy, and potential risks.