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Evolution and Comparative Analysis of Clinical Trials on Psilocybin in the Treatment of Psychopathologies: Trends in the EU and the US

Ana Flavia Burlec, Cornelia Mircea, Irina Macovei, Andrei Călin, Monica Hăncianu, Andreia Corciovă

Journal of Clinical Medicine September 19, 2025 DOI: 10.3390/jcm14186613 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Mixed-methods comparative analysis Qualitative Peer reviewed
Topics Psilocybin
Key points The US has substantially more psilocybin trials across early and advanced phases than the EU, reflecting differences in regulation, funding, and sociocultural attitudes.

Abstract

Background/Objectives: This study examines the development of clinical trials investigating psilocybin for the treatment of psychopathologies, with a comparative focus on the United States (US) and the European Union (EU). The objective is to identify regional differences in trial progression, research infrastructure, and regulatory frameworks.

Methods: A mixed-methods approach was applied, combining case studies, qualitative and quantitative research. Key variables included trial phase, geographical distribution, demographic factors, funding, governmental support, and public health policies.

Results: The US demonstrated a substantially higher number of psilocybin trials across both early and advanced phases. This reflects a strong research infrastructure, growing financial investment, and increasing interest in psychedelic-assisted therapies. In contrast, the EU showed fewer trials and slower advancement, reflecting a more cautious stance that emphasizes patient safety and therapeutic efficacy. These divergences are shaped by differences in regulation, funding mechanisms, and sociocultural attitudes toward psychedelics in psychiatry.

Conclusion: This comparative analysis highlights the uneven pace of psilocybin research across different regions. It also emphasizes the importance of international collaboration, harmonization of public health policies, and the development of standardized procedures prioritizing safety and effectiveness. Integrating psilocybin-assisted interventions into psychiatric practice has the potential to expand treatment options and strengthen mental health care, but coordinated global efforts are essential to ensure both scientific rigor and patient protection.

Comparable studies

Other qualitative studies on psilocybin, most cited first.

Study Year Design Participants
Patients’ Accounts of Increased “Connectedness” and “Acceptance” After Psilocybin for Treatment-Resistant Depression Patients with treatment-resistant depression enrolled in an open-label trial of psilocybin 2017 Qualitative study n = 20
Patient Experiences of Psilocybin-Assisted Psychotherapy: An Interpretative Phenomenological Analysis Adults aged 22 to 69 with clinically elevated anxiety associated with a cancer diagnosis 2017 Qualitative study n = 13
Psychedelic therapy for smoking cessation: Qualitative analysis of participant accounts Participants who completed a psilocybin-facilitated smoking cessation pilot study 2018 Qualitative follow-up study using semi-structured interviews and thematic analysis n = 12
Response of cluster headache to psilocybin and LSD Cluster headache patients who used psilocybin or LSD 2006 Qualitative study n = 53
Cancer at the Dinner Table: Experiences of Psilocybin-Assisted Psychotherapy for the Treatment of Cancer-Related Distress Adult participants with clinically elevated anxiety associated with a cancer diagnosis 2017 Qualitative study using interpretative phenomenological analysis n = 13

Citations in the library

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