Translational Psychiatry
August 2, 2022
Federico Cavanna, Stephanie Müller, Laura Alethia de la Fuente et al.
130 citations
A double-blind placebo-controlled trial tested the effects of a low (0.5 g) dose of dried psilocybin mushrooms on 34 individuals beginning a microdosing protocol. The active dose produced more intense acute subjective effects than placebo, but only among participants who correctly guessed their condition. These effects coincided with reduced EEG theta-band power and preserved Lempel-Ziv broadband signal complexity. No evidence was found for enhanced well-being, creativity, or cognitive function; instead, small changes toward cognitive impairment appeared. The findings suggest that expectation, not the drug itself, accounts for many anecdotal benefits attributed to psilocybin microdosing.
Neuroscience of consciousness
January 1, 2025
Christopher Timmermann, James W Sanders, David Reydellet et al.
19 citations
The psychedelic 5-MeO-DMT can, in its most extreme cases, produce a complete absence of self-experience and other perceptual content while preserving a quality of aroused, waking awareness. In an exploratory observational study in naturalistic ceremonial settings, micro-phenomenological interviews, questionnaires, and EEG recordings revealed a dynamic progression of effects, including variable disruptions of bodily and narrative self, reduced phenomenal distinctions, and visual imagery. EEG showed global alpha and posterior beta power reductions, suggesting inhibition of top-down brain models. The findings indicate 5-MeO-DMT's potential as a pharmacological model for deconstructed consciousness, though retrospective questionnaires have limitations.
bioRxiv (Cold Spring Harbor Laboratory)
December 7, 2021
Federico Cavanna, Stephanie Müller, Laura Alethia de la Fuente et al.
8 citations
preprint
A double-blind placebo-controlled trial tested the effects of a low (0.5 g) sub-hallucinogenic dose of dried psilocybin mushrooms in 34 individuals planning to microdose. Acute subjective effects were significantly stronger with the active dose than with placebo, possibly due to unblinding. For other measures—including creativity, perception, cognition, and brain activity—the results were null or showed a trend toward cognitive impairment and, in electroencephalography, reduced theta band spectral power. These findings suggest that expectation effects may account for some of the anecdotal benefits people report from microdosing psilocybin.
bioRxiv (Cold Spring Harbor Laboratory)
February 22, 2022
Camila Sanz, Federico Cavanna, Stephanie Müller et al.
1 citation
preprint
Low doses of psilocybin (microdoses) can be detected in natural speech. In a double-blind, placebo-controlled experiment, participants given 0.5 g of psilocybin mushrooms showed significant differences in verbosity and sentiment scores compared to placebo, though semantic variability did not differ. Machine learning classifiers using these speech metrics distinguished between the psilocybin and placebo conditions with high accuracy (AUC≈0.8). These findings suggest that unconstrained natural language may serve as a practical, low-cost tool for monitoring microdosing effects, addressing limitations of existing questionnaires designed for larger psychedelic doses.