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Too big to fail? Comparing effect sizes of MDMA assisted therapy to unmasking bias

Balázs Szigeti, Ellen Bradley, Joshua Woolley

preprint DOI: 10.31219/osf.io/ujtpf (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Theoretical or quantitative analysis
Topics MDMA
Key points Argues that unmasking bias is larger than the treatment versus control effect size for MDMA, suggesting that MDMA-AT's effect sizes are not too large to be due to unmasking.

Abstract

On August 9th the US Food and Drug Administration’s (FDA) rejected 3,4-methylenedioxymethamphetamine assisted therapy (MDMA-AT) as a treatment for post-traumatic stress disorder (PTSD), despite seemingly positive trial results. A major reason cited was functional unmasking, which combined with enthusiasm about MDMA, raised concerns about the objectivity of these trials. Here, we define what is 'unmasking bias' and calculate its magnitude for two drugs, ketamine and escitalopram, where data was available from the literature. Our results show that unmasking bias is larger than the treatment vs control effect size for MDMA. These findings do not prove that effects of MDMA-AT are entirely or even partially due to unmasking, however, our findings do indicate that MDMA-AT’s effect sizes are not too large to be due to unmasking.

Comparable studies

Other theoretical and historical papers on MDMA, most cited first.

Study Year Design Participants
Differences Between the Mechanism of Action of MDMA, MBDB, and the Classic Hallucinogens. Identification of a New Therapeutic Class: Entactogens 1986 Theoretical or philosophical paper
The Background and Chemistry of MDMA 1986 Historical analysis
The origin of MDMA (ecstasy) revisited: the true story reconstructed from the original documents* Original documents in Merck's historical archive in Darmstadt, Germany, years 1900–1960 2006 Historical analysis
Distinct neural mechanisms for the prosocial and rewarding properties of MDMA 2019 Theoretical or philosophical paper
How could MDMA (ecstasy) help anxiety disorders? A neurobiological rationale 2009 Theoretical or philosophical paper

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