Evidence map›Paper›PMID 31221820›Full record

ReviewPharmacological reviews2019

REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics.

R L Carhart-Harris, K J Friston

Registry-linked trialOpen access · hybridAbstract readReview
PubMed Full text at PMC Publisher
In one paragraph

Review in Pharmacological reviews, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT07614581 (Intra-Sessional Autonomic Arc Detection Using Continuous HRV and EDA Monitoring in Adults Undergoing Ketamine-Assisted Therapy for PTSD), which is not on this map. Cited by 448 papers, 8 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
448citing papers in PubMed, 8 pooled it
85.3field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT07614581 not yet recruitingnot on this mapstarted 2026, after this paper: background citation

Intra-Sessional Autonomic Arc Detection Using Continuous HRV and EDA Monitoring in Adults Undergoing Ketamine-Assisted Therapy for PTSD: A Prospective Observational Signal Characterisation Pilot Study

TypeobservationalSponsorAdriaan Dirk van der WartRan2026 to 2026Enrolled5ConditionsPost-Traumatic Stress DisorderArmsContinuous wearable physiological monitoring (EmbracePlus, Empatica), Ketamine-assisted therapy (independently arranged), Structured pre- and post-session interviews
3 · Its place in the literature

Who cites it

448 citing papers in PubMed, 8 syntheses or guidelines pooled it, 1,080 citations in OpenAlex.

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  7. Catalyst for change: Psilocybin's antidepressant mechanisms-A systematic review.Journal of psychopharmacology (Oxford, England) · 2025
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388 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 2 institutions in 1 country.

R L Carhart-HarrisCentre for Psychedelic Research, Division of Brain Sciences, Imperial College London, London, United Kingdom (R.L.C.-H.); and Institute of Neurology, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom (K.J.F.) r.carhart-harris@imperial.ac.uk.
K J FristonCentre for Psychedelic Research, Division of Brain Sciences, Imperial College London, London, United Kingdom (R.L.C.-H.); and Institute of Neurology, Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom (K.J.F.).
University College London · GBWellcome Centre for Human Neuroimaging · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This paper formulates the action of psychedelics by integrating the free-energy principle and entropic brain hypothesis. We call this formulation relaxed beliefs under psychedelics (REBUS) and the anarchic brain, founded on the principle that-via their entropic effect on spontaneous cortical activity-psychedelics work to relax the precision of high-level priors or beliefs, thereby liberating bottom-up information flow, particularly via intrinsic sources such as the limbic system. We assemble evidence for this model and show how it can explain a broad range of phenomena associated with the psychedelic experience. With regard to their potential therapeutic use, we propose that psychedelics work to relax the precision weighting of pathologically overweighted priors underpinning various expressions of mental illness. We propose that this process entails an increased sensitization of high-level priors to bottom-up signaling (stemming from intrinsic sources), and that this heightened sensitivity enables the potential revision and deweighting of overweighted priors. We end by discussing further implications of the model, such as that psychedelics can bring about the revision of other heavily weighted high-level priors, not directly related to mental health, such as those underlying partisan and/or overly-confident political, religious, and/or philosophical perspectives. SIGNIFICANCE STATEMENT: Psychedelics are capturing interest, with efforts underway to bring psilocybin therapy to marketing authorisation and legal access within a decade, spearheaded by the findings of a series of phase 2 trials. In this climate, a compelling unified model of

Indexed as

AnimalsBrainCultureHallucinogensHumansModels, NeurologicalHallucinogens

Identifiers

PMID31221820
PMCPMC6588209
OpenAlexW2949457836

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.