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Finding the self by losing the self: Neural correlates of ego-dissolution under psilocybin

Alexander V. Lebedev, Martin Lövdén, Gidon Rosenthal, Amanda Feilding, David Nutt, Robin Carhart-Harris

Human Brain Mapping May 22, 2015 DOI: 10.1002/hbm.22833 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Placebo-controlled study Peer reviewed
Sample size 15
Population Healthy subjects
Intervention Psilocybin
Dose 2 mg
Duration Twelve-minute functional MRI scans on two occasions
Topics Psilocybin Ego dissolution
Keywords Salience neuroscience Hallucinogen
Citations 347
Key points Psilocybin-induced ego-dissolution was associated with decreased functional connectivity between the medial temporal lobe and high-level cortical regions, disintegration of the salience network, and reduced interhemispheric communication.

Abstract

Ego-disturbances have been a topic in schizophrenia research since the earliest clinical descriptions of the disorder. Manifesting as a feeling that one's "self," "ego," or "I" is disintegrating or that the border between one's self and the external world is dissolving, "ego-disintegration" or "dissolution" is also an important feature of the psychedelic experience, such as is produced by psilocybin (a compound found in "magic mushrooms"). Fifteen healthy subjects took part in this placebo-controlled study. Twelve-minute functional MRI scans were acquired on two occasions: subjects received an intravenous infusion of saline on one occasion (placebo) and 2 mg psilocybin on the other. Twenty-two visual analogue scale ratings were completed soon after scanning and the first principal component of these, dominated by items referring to "ego-dissolution", was used as a primary measure of interest in subsequent analyses. Employing methods of connectivity analysis and graph theory, an association was found between psilocybin-induced ego-dissolution and decreased functional connectivity between the medial temporal lobe and high-level cortical regions. Ego-dissolution was also associated with a "disintegration" of the salience network and reduced interhemispheric communication. Addressing baseline brain dynamics as a predictor of drug-response, individuals with lower diversity of executive network nodes were more likely to experience ego-dissolution under psilocybin. These results implicate MTL-cortical decoupling, decreased salience network integrity, and reduced inter-hemispheric communication in psilocybin-induced ego disturbance and suggest that the maintenance of "self"or "ego," as a perceptual phenomenon, may rest on the normal functioning of these systems.

In the evidence

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  • Psilocybin-induced ego dissolution was associated with decreased medial temporal-to-cortical connectivity, salience network disintegration, and reduced interhemispheric communication.

    Synthesized

Comparable studies

Other randomized controlled trials on ego dissolution, most cited first.

Study Year Design Participants
Me, myself, bye: regional alterations in glutamate and the experience of ego dissolution with psilocybin. Human participants 2020 Double-blind, placebo-controlled, parallel group design
LSD, madness and healing: Mystical experiences as possible link between psychosis model and therapy model. Healthy volunteers 2023 Randomized, double-blind, placebo-controlled, crossover design n = 24
Effective Connectivity of Functionally Anticorrelated Networks Under Lysergic Acid Diethylamide. Healthy adults 2023 Experimental study with placebo control n = 25
Unique Psychological Mechanisms Underlying Psilocybin Therapy Versus Escitalopram Treatment in the Treatment of Major Depressive Disorder Patients with moderate-to-severe major depressive disorder 2024 Phase 2, double-blind, randomized, active comparator controlled trial
Dynamic Functional Hyperconnectivity After Psilocybin Intake Is Primarily Associated With Oceanic Boundlessness. Healthy participants 2024 Randomized controlled trial n = 49

Citations in the library

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