Skepticism about Recent Evidence That Psilocybin ?Liberates? Depressed Minds

A recent paper in Nature Medicine found that psilocybin therapy in patients with depression decreased brain network modularity (measured with task-free functional magnetic resonance imaging), an effect supposedly not found with the selective serotonin reuptake inhibitor S-citalopram. This decrease in network modularity also correlated with depression. Here, we raise several issues with this paper, including inconsistencies in reports of the primary clinical outcome, statistical flaws including a one-tailed test, nonsignificant interaction, and regression to the mean, the ambiguity and overinterpretation of resting state data, and a missing reference for a conceptually similar study that exemplifies why a one-tailed test cannot be justified. Together, these issues make us question the uniqueness and impact of these findings, as well as the unwarranted media hype that they generated.

Automated summary

This article raises several issues with a recent paper published in Nature Medicine, including inconsistencies in the reporting of clinical outcomes, statistical flaws, ambiguity and overinterpretation of resting state data, and the lack of a reference for a conceptually similar study. These issues cast doubt on the uniqueness and impact of the findings.