Topic starter
There is a new scientific article that investigates how psilocybin changes the electrical activity of the brain, and how those changes relate to what people subjectively feel during the experience.
In it, we discuss:
The researchers conducted a double-blind, randomized, crossover, and placebo-controlled study with 25 healthy participants. Each participant received either psilocybin or placebo in two sessions. Around the peak effect, 10-minute resting EEG measurements were taken, through which the researchers examined changes in brain waves, connectivity within the default mode network, and local networks in frontal and parietal brain regions.
The real focus of this article is not on the clinical improvement of patients, but on better understanding the neurophysiology of psilocybin. This is important because such brain signals could potentially help later to identify predictors or biomarkers for who responds strongly or differently to psilocybin.
The results show that psilocybin reduced slow brain waves and increased faster activity. More specifically, EEG power decreased in theta and alpha frequencies, while power in beta, gamma1, and gamma2 increased compared to placebo. Additionally, the researchers found greater connectivity within the default mode network and in a local parietal network under psilocybin.
It also appeared that these EEG changes were associated with subjective experience, measured with the Altered States of Consciousness Questionnaire. Furthermore, the authors describe that certain baseline EEG characteristics may be predictive of how intensely or in what way someone experiences the psilocybin experience. This makes this article particularly relevant for the personalization of future treatments.
It is important to note, however, that this study was conducted on healthy volunteers and therefore does not directly demonstrate whether these EEG changes also explain why psilocybin is clinically effective for depression or other conditions. Moreover, it is a relatively small study, and the step from neurophysiological correlations to actual treatment prediction remains provisional.
In one sentence: this article shows that psilocybin causes measurable changes in brain waves and network connectivity, and that those changes are clearly related to the intensity and nature of the subjective experience.
Spoiler
New article description
Abstract
Background: Recent advancements in psychedelic research have highlighted psilocybin's potential therapeutic benefits for various mental disorders. Understanding its effects on brain function and identifying predictors of individual responses are essential for developing effective treatments.
Methods: This double-blind, randomized, crossover, and placebo-controlled study enrolled 25 healthy individuals (18 males, 7 females, average age 24.44 years). Participants underwent two sessions involving administration of either psilocybin (oral dose of 10-20 mg) or placebo. Ten-minute resting EEG recordings were taken at baseline and post-administration peaks, focusing on EEG power and connectivity in the default-mode network (DMN) and localized cortical networks in the frontal and parietal cortices. Additionally, we investigated whether baseline EEG features could predict subjective experiences during the psilocybin condition.
Results: Psilocybin significantly decreased EEG power in slow frequency bands (theta and alpha) and increased power in fast frequency bands (beta, gamma1, gamma2) compared to placebo. Connectivity analyzes revealed increased connectivity in the DMN and localized parietal network under psilocybin. Subjective experiences, as measured by the Altered States of Consciousness Questionnaire, showed positive correlations with changes in EEG power and connectivity.
Conclusions: Psilocybin induces significant changes in brain function, characterized by altered EEG power and connectivity. These changes correlate strongly with subjective experiences, supporting psilocybin's potential for treating mental disorders. The predictive value of baseline EEG features for subjective alterations suggests that specific brain activity patterns may serve as biomarkers for tailoring psilocybin therapy in clinical settings. This study enhances our understanding of psilocybin's neurophysiological impacts and informs future therapeutic applications.
Keywords: Altered states of consciousness; Default mode network; EEG; Placebo; Psilocybin.
Posted : 18 March 2026 14:47