Evidence versus expectancy: the development of psilocybin therapy
BJPsych Bulletin – May 29, 2023
Source: OpenAlex
Summary
After 25 years of development, psilocybin therapy shows promising early clinical trial evidence for treatment-resistant depression, a significant advance in Medicine. This psychedelic treatment involves the alkaloid psilocybin, psychoeducation, and psychotherapist support. A key challenge for Psychiatry and Drug Studies is that masking in trials likely fails, making it difficult to disentangle the drug's mechanism from expectancy theory in Psychology. Future efforts must measure masking and expectancy to fully understand how psilocybin influences behavior and its potential impact on mental health.
Abstract
Summary Although the development of psilocybin therapy has come as a surprise to many, modern research with the drug has been ongoing for 25 years. Psilocybin therapy is composed of psilocybin dosing sessions embedded within a wider process of psychoeducation, psychological support and integration. Early phase clinical trial evidence is promising, particularly for treatment-resistant depression. However, masking probably fails and expectancy effects may be a part of the mechanism of change. Disambiguating between drug and expectancy effects is a necessary part of the development process, yet this is difficult if masking fails. Hitherto, masking and expectancy have not been routinely measured in psilocybin or other medication trials. Doing so represents an opportunity for research and may influence psychiatry more widely. In this opinion piece I summarise the clinical development process of psilocybin therapy thus far, discussing the hope, the hype, the challenges and the opportunities along the way.