Reporting practices in psilocybin-assisted therapy trials for depression: A descriptive review and temporal overview

Background Research on psilocybin's antidepressant effects has been investigated rigorously over the last 20 years. Psilocybin has been used in both major depressive disorder (MDD) and treatment resistant depression (TRD) cohort with promising results. Aims The aim of this review was to summarize the reporting practices used in psilocybin-assisted therapy (PAT) trials for MDD and TRD. By comparing completed and ongoing PAT, a temporal summary of how reporting practices are projected to change was also investigated. Findings The review found several areas of improvement: overrepresentation of participants with previous psychedelic experiences (22.4% of participants); inconsistent reporting of preparatory and integration sessions (reported as number of hours instead of number of sessions); lack of reporting on blinding success for therapists (10%), blinding success for participants (16.7%), therapist fidelity (6.7%), and expectancy (6.7%). Besides this, standardization across trials was found in areas such as depression scales used (increased use of MADRS), intervention for control (increased use of 25 mg) and intervention groups (increased use of 1 and 0 mg). Conclusion While reporting practices are becoming more standardized in some key areas, other areas in PAT trials are often omitted or not stated explicitly. Thus, this review highlights the need for future research to investigate blinding success, therapist fidelity, and expectancy more thoroughly, as well as including more participants without previous experience with psychedelics.