Frontiers in Human Neuroscience
June 14, 2016
Matthew M. Nour, Lisa Evans, David Nutt et al.
476 citations
A new questionnaire, the Ego-Dissolution Inventory (EDI), reliably measures the experience of ego-dissolution—a temporary loss of the sense of self—during psychedelic drug use. The EDI shows strong psychometric properties, including internal consistency and construct validity, and its scores closely relate to the subjective psychedelic experience. This tool enables researchers to investigate the brain mechanisms underlying ego-dissolution, which may inform psychedelic-assisted psychotherapy and improve understanding of psychosis.
Acta Psychiatrica Scandinavica
June 19, 2018
David Erritzøe, Leor Roseman, Matthew M. Nour et al.
268 citations
In patients with treatment-resistant depression, psilocybin therapy was associated with a decrease in neuroticism and increases in extraversion and openness three months later. These personality shifts moved toward normative population averages and were predicted by the degree of insight experienced during the psilocybin session. Conscientiousness showed trend-level increases, while agreeableness did not change. The pattern partly resembles changes seen with conventional antidepressants, but the pronounced rises in extraversion and openness may be more specific to psychedelic therapy.
Psychopharmacology
August 8, 2022
Rosalind Watts, Hannes Kettner, Dana Geerts et al.
159 citations
A new scale, the Watts Connectedness Scale (WCS), measures a three-dimensional sense of connectedness to self, others, and the wider world. Analysis of data from 1,226 participants in online surveys and a randomized controlled trial of 52 people with major depressive disorder showed the scale has good internal consistency and construct validity. After psychedelic use, total connectedness scores increased significantly, and acute experiences of mystical experience, emotional breakthrough, and communitas correlated with these changes. In the trial, psilocybin-assisted therapy produced greater increases in WCS scores than daily escitalopram. The WCS may sensitively capture therapeutically relevant psychological changes.
The British Journal of Psychiatry
March 1, 2017
Matthew M. Nour, Robin Carhart‐Harris
90 citations
Altered self-experiences, which occur in some psychiatric conditions and can be induced by psychoactive drugs or spiritual practices, are now being studied through a neuroscience framework that combines functional neuroimaging with altered states from psychedelic drugs. This emerging understanding may significantly benefit psychiatry.
December 4, 2025
Avery Ostrand, Matthew M. Nour, Christopher Timmermann et al.
2 citations
preprint
The term 'psychedelic' was coined in 1956 from Greek roots meaning 'soul-manifesting' or 'soul-illuminating,' intended to name a drug category defined by its ability to induce a characteristic subjective state. This study examined the main subjective effects of psilocybin, ketamine, and MDMA. Over two hundred participants rated items about their experiences with all three drugs. Factor analyses revealed three or four independent dimensions of subjective experience. A machine learning classifier successfully predicted which drug a person had taken from the effects reported, confirming that the three drugs produce categorically distinct experiences: psilocybin induces visions and psychological insight, ketamine induces dissociation, and MDMA induces pro-social feelings such as love. Psilocybin is thus an exemplar psychedelic drug, definable by its induction of a psychedelic state characterized by visions and insight.
Neuropsychopharmacology Reports
March 13, 2024
Keisuke Kusudo, Hideaki Tani, Kengo Yonezawa et al.
2 citations
A Japanese version of the Ego-Dissolution Inventory (EDI) was developed through a translation and back-translation process following international guidelines. Two Japanese psychiatrists independently translated the original English EDI, reconciled differences, and had the resulting version back-translated into English. The original authors reviewed and approved the back-translated version after iterative revisions. The final Japanese EDI is intended to help assess ego-dissolution experiences during psychedelic-assisted therapy in Japanese-speaking populations. Further research is needed to test the reliability and validity of this new instrument.
International Journal of Latin American Religions
June 9, 2023
Robson Savoldi, Antônio Roazzi, José Arturo Costa Escobar et al.
2 citations
Mysticism significantly enhances well-being, with 75% of participants in a study reporting improved life satisfaction after engaging in mystical experiences. In a sample of 500 individuals, psychometric assessments utilized structural equation modeling to confirm the construct validity of these experiences. The interplay between philosophy and social psychology revealed that psychedelics, particularly alkaloids, can facilitate profound insights into the self—bridging the id, ego, and super-ego. This highlights the potential of mystical experiences as therapeutic tools within developmental psychology and theology.