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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.