Imperial College London
Alternate

Professor Robin Carhart-Harris

Faculty of Medicine, Department of Brain Sciences

Visiting Professor
 
 
 
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Contact

 

+44 (0)20 7594 7992r.carhart-harris

 
 
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Assistant

 

Miss Bruna Cunha +44 (0)20 7594 7992

 
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Location

 

Burlington DanesHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Nour:2016:10.3389/fnhum.2016.00269,
author = {Nour, M and Evans, L and Nutt, D and Carhart-Harris, R},
doi = {10.3389/fnhum.2016.00269},
journal = {Frontiers in Human Neuroscience},
title = {Ego-dissolution and psychedelics: validation of the Ego-Dissolution Inventory (EDI)},
url = {http://dx.doi.org/10.3389/fnhum.2016.00269},
volume = {10},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Aims: The experience of a compromised sense of “self”, termed ego-dissolution, is a key feature of the psychedelic experience. This study aimed to validate the Ego-Dissolution Inventory (EDI), a new 8-item self-report scale designed to measure ego-dissolution. Additionally, we aimed to investigate the specificity of the relationship between psychedelics and ego-dissolution.Method: Sixteen items relating to altered ego-consciousness were included in an internet questionnaire; eight relating to the experience of ego-dissolution (comprising the EDI), and eight relating to the antithetical experience of increased self-assuredness, termed ego-inflation. Items were rated using a visual analog scale. Participants answered the questionnaire for experiences with classical psychedelic drugs, cocaine and/or alcohol. They also answered the seven questions from the Mystical Experiences Questionnaire (MEQ) relating to the experience of unity with one’s surroundings.Results: Six hundred and ninety-one participants completed the questionnaire, providing data for 1828 drug experiences (1043 psychedelics, 377 cocaine, 408 alcohol). Exploratory factor analysis demonstrated that the eight EDI items loaded exclusively onto a single common factor, which was orthogonal to a second factor comprised of the items relating to ego-inflation (rho = −0.110), demonstrating discriminant validity. The EDI correlated strongly with the MEQ-derived measure of unitive experience (rho = 0.735), demonstrating convergent validity. EDI internal consistency was excellent (Cronbach’s alpha 0.93). Three analyses confirmed the specificity of ego-dissolution for experiences occasioned by psychedelic drugs. Firstly, EDI score correlated with drug-dose for psychedelic drugs (rho = 0.371), but not for cocaine (rho = 0.115) or alcohol (rho = −0.055). Secondly, the linear regression line relating the subjective intensity of the experience to ego-dissolution was significantly steep
AU  - Nour,M
AU  - Evans,L
AU  - Nutt,D
AU  - Carhart-Harris,R
DO  - 10.3389/fnhum.2016.00269
PY  - 2016///
SN  - 1662-5161
TI  - Ego-dissolution and psychedelics: validation of the Ego-Dissolution Inventory (EDI)
T2  - Frontiers in Human Neuroscience
UR  - http://dx.doi.org/10.3389/fnhum.2016.00269
UR  - http://hdl.handle.net/10044/1/33059
VL  - 10
ER  -
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