Placebo Effects & Blinding in Psychedelic Trials
Balázs Szigeti, PhD
Tuesday 8 September, 2026 7PM CEST (6PM BST, 1PM ET, 10AM PT)
Online via Zoom
Add to Calendar
Psychedelic trials routinely face a specific methodological problem: functional unblinding. Because psychedelic drugs produce such intense and unmistakable psychoactive effects, patients and often the researchers assessing them can readily identify who received the active treatment, even in trials formally designed as blinded. This was a major factor in the FDA’s rejection of MDMA-assisted therapy for the treatment of post-traumatic stress disorder.
In this talk, we will examine how functional unblinding shapes the design and interpretation of psychedelic trials, with particular attention to the problem of missing placebo response. We’ll critically assess when blinding genuinely matters for answering a given research question, and when unblinding may not meaningfully undermine a study’s conclusions at all. We’ll also explore how expectancy and unblinding interact with one another, and consider practical ways forward for evaluating treatments that may simply be ‘unblindable’ by nature.
Your Key Insights and Takeaways
- Understanding how functional unblinding arises in psychedelic trials and why it’s difficult to design around
- The role missing placebo response plays in interpreting trial outcomes
- When blinding is essential to answering a research question, and when its absence may not compromise the findings
- How expectancy effects interact with unblinding to shape reported outcomes
- Emerging approaches and methodological alternatives for evaluating treatments that resist conventional blinding
Designed for Professionals Like You
- Researchers and clinical trial designers working on psychedelic-assisted therapy studies
- Clinicians and therapists seeking to understand the evidentiary basis and limitations of the trials informing their practice
- Regulatory affairs professionals and those navigating FDA or other regulatory review processes for psychedelic treatments
- Academics and students in clinical psychology, psychiatry, or pharmacology interested in trial methodology
- Anyone seeking a clear eyed, critical understanding of the evidence base behind psychedelic-assisted therapies
