Characteristics of Ongoing Clinical Trials of Psychogenic Substances for Psychiatric Disorders

With a rapid rise in clinical trials investigating psychogenic substances, the field faces considerable concerns regarding transparency and conflicts of interest. This study aims to systematically characterize ongoing NIH-registered clinical trials investigating psychogenic substances for psychiatric disorders as of late 2024, including research protocols, institutional settings, and funding sources.

This cross-sectional analysis evaluated ongoing trials from ClinicalTrials.gov that studied psychogenic substances-defined as compounds significantly affecting perception, cognition, or emotion-for psychiatric conditions. Data collected included substance class, targeted diagnoses, trial phase, geographic location, study design (eg, blinding), recruitment status, and funding sources.

A total of 181 trials met the inclusion criteria, with the majority in phase 2 (n=93; 51.4%) or phase 1 (n=33; 18.2%). The most frequently studied substances were psilocybin (n=64; 35.4%) and ketamine (n=61; 33.7%). Trials were notably concentrated within a small number of leading academic institutions. Most trials (n=148; 81.2%) listed their funding source as "other," of which 127 (86.4%) were sponsored by universities or university-affiliated institutions. Blinding was not reported in 38.7% (n=70) of trials. The primary conditions studied were major depressive disorder (n=94; 51.9%), posttraumatic stress disorder (n=38; 21.0%), and alcohol use disorder (n=21; 11.6%).

Ongoing clinical trials of psychogenic substances for psychiatric disorders are largely concentrated at select institutions and primarily focus on psilocybin and ketamine. The majority lack clear disclosure of funding sources, highlighting a need for enhanced transparency to build trust and facilitate the ethical advancement of this rapidly evolving area of psychiatric research.