bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2020.06.09.142802

How does it feel to be on psilocybin? Dose-response relationships of subjective experiences in humans.

Hirschfeld, T.·Schmidt, T. T.
View original source ↗Export metadata ↓

Abstract

Psilocybin is the active component of magic mushrooms and is well known for its psychoactive properties. Different questionnaires have been developed to systematically quantify altered states of consciousness induced by psychoactive drugs. The aim of this study was to obtain the dose-response relationships of the subjective experiences induced by psilocybin in healthy study participants. For this purpose, we applied a linear meta-regression approach on questionnaire ratings after oral administration of psilocybin in a controlled setting. Data was obtained from The Altered States Database, which contains psychometric data extracted from peer-reviewed articles published in MEDLINE-listed journals that used standardized and validated questionnaires. Our meta-analysis included data of the Altered States of Consciousness Rating Scale, the Mystical Experience Questionnaire (MEQ30), and the Hallucinogen Rating Scale (HRS). We used the Robust Variance Estimation Framework to obtain linear dose-response relationship estimates for each dimension of the given questionnaires. Ratings on most dimensions and subscales of the included questionnaires correlated positively with dose. Since subjective experiences are not only determined by dose, but also by individual differences and environmental factors, our results do not necessarily generalize to recreational use, as our analyses are based on data from controlled laboratory experiments. The paper at hand could serve as a general literature citation for the use of psilocybin in experimental and clinical research, especially for the comparison of expected and observed subjective drug experiences.

Source connections

Explore related subjects

neurosciencePreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Hirschfeld, T., Schmidt, T. T.. 2020-06-11. How does it feel to be on psilocybin? Dose-response relationships of subjective experiences in humans.. https://doi.org/10.1101/2020.06.09.142802

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Distinguishing evidence accumulation from choice confidence in neural signatures of perceptual decision making

Human electrophysiology research has identified the centro-parietal positivity (CPP) as an apparent neural correlate of sensory evidence accumulation during perceptual decision-making. The CPP has also been shown to closely scale with subjective confidence. Coupled with the fact of its domain-generality and lack of choice selectivity, this observation raises the possibility that the CPP might in fact trace subjective confidence rather than cumulative evidence, two quantities that are closely correlated in most experiments. To disentangle confidence from cumulative evidence, we used predictive cues with 80% validity to manipulate prior expectations of participants during a contrast discrimination task while recording electroencephalography (EEG). At the time of decision termination, confidence is expected to reach a higher level for validly cued versus invalidly cued choices, whereas the opposite would be expected of a cumulative evidence signal due to biased decision starting points. As expected, valid cues led to faster, more accurate and more confident responses compared to invalid and neutral cues. At the neural level, cues produced systematic increases in preparation of the expected action prior to evidence onset as indexed by premotor mu/beta activity, consistent with cue-biased criterion adjustments. The pre-response CPP amplitude was significantly reduced for validly cued choices and the effect remained even when matching for confidence. Together these findings suggest that the CPP is not a direct read-out of subjective confidence, but an evidence accumulation signal that contributes to both decision formation and confidence estimation.

neuroscience↗
bioRxiv2026

A Neurocompliant Ionic Conductive Hydrogel Orchestrates Glial and Vascular Remodeling to Mitigate Traumatic Brain Injury

Developing conductive scaffolds for neural regeneration is often hindered by the cytotoxicity and mechanical mismatch inherent to conventional electronic fillers. Here, we report an ultrasoft ionically conductive hydrogel engineered by grafting choline-based bioionic liquids (BIL) onto fish gelatin (FiBGel). Systematic optimization yields brain-mimetic conductivity (0.25-0.68 S/m), elastic moduli (0.6-0.9 kPa), and physiological water content (72-81%). In 3D culture, the matrix drives spontaneous neurogenesis, achieving ~90% MAP2+ neurons with robust calcium signaling, while concurrently supporting endothelial network formation. We report the first intracerebral administration of a BIL hydrogel, demonstrating remarkable biocompatibility and immunomodulation. In a traumatic brain injury model, a single FiBGel dose halves reactive astrogliosis, enhances cortical revascularization, and limits lesion cavity expansion. Leveraging an FDA-recognized micronutrient, FiBGel offers a translatable strategy that integrates neuromechanics, conductivity, immune modulation, and vascular support within one injectable scaffold for minimally invasive treatment of brain injuries.

neuroscience↗
bioRxiv2026

Changes in anterior cingulate connectivity associated with response to antidepressant treatment for major depressive disorder

Background: Resting-state functional connectivity (rsFC) involving the anterior cingulate cortex (ACC) and the hippocampal formation has been implicated in major depressive disorder (MDD) and antidepressant response. However, it remains unclear whether connectivity changes in distinct ACC subdivisions and hippocampal formation reflect general antidepressant effects or are specifically associated with clinical improvement. Methods: Forty-one, unmedicated adults with MDD underwent functional MRI before and after 8 weeks of sertraline or bupropion treatment. Seed-based rsFC analyses examined subgenual ACC (sgACC), pregenual ACC (pgACC), dorsal ACC (dACC), and hippocampal formation connectivity. Linear mixed-effects models tested whether connectivity change was associated with treatment response, remission, and dimensional improvement in depressive symptoms. Results: Thirty individuals (73.2%) responded to treatment and 26 (63.4%) achieved remission. Overall, rsFC decreased pre- to post-treatment between (1) dACC and pgACC (but not sgACC and hippocampal formation) and (2) cortical regions primarily involving default mode and frontoparietal networks. When considering treatment response, differences in sgACC and pgACC connectivity with temporal and inferior frontal regions emerged (increased in responders vs. decreased in non-responders). Remission was similarly associated with increased sgACC connectivity with temporal and prefrontal regions, and increased sgACC connectivity with temporal cortical regions related to greater reductions in depressive symptoms. Conclusions: Antidepressant treatment was associated with distinct patterns of ACC connectivity change, with general reductions in dorsal and pregenual connectivity but increases in subgenual and pregenual connectivity associated with favorable clinical outcomes. Findings suggest that changes in sgACC/pgACC connectivity are particularly relevant to antidepressant treatment response. Keywords: Major depressive disorder; Resting-state functional connectivity; Anterior cingulate cortex; Antidepressant treatment; Treatment response; Subgenual anterior cingulate cortex.

neuroscience↗