Multidimensional Ego-Dissolution Assessment (MEDA): Scale Development and Substance-Specific Comparisons

Ego-dissolution—a sense of losing one's usual self-boundaries—is considered important in psychedelic therapy, but existing scales may miss its complexity. A new 34-item measure, the Multidimensional Ego-Dissolution Assessment (MEDA), was tested on 207 people who had profound experiences with ayahuasca, DMT, LSD, or psilocybin. Factor analysis identified six distinct dimensions: dissolving of identity, experiences of eternity, dissolving of physical body, dissolving into environment, clarity about life and purpose, and pleasure. Ayahuasca and DMT produced higher dissolution scores than LSD and psilocybin on four factors, while all substances yielded similarly high scores on insight and pleasure. Dosage did not affect results. The findings suggest that different psychedelics may produce distinct ego-dissolution profiles, which could guide therapeutic choices.

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Abstract

Rationale: Ego-dissolution represents a key therapeutic mechanism in psychedelic-assisted therapy, yet current measurement approaches may inadequately capture its multidimensional nature.Objective: To develop and validate the Multidimensional Ego-Dissolution Assessment (MEDA) and examine substance-specific patterns across classical psychedelics.Methods: Items from three validated scales (Ego-Dissolution Inventory, Mystical Experience Questionnaire, 5D-Altered States of Consciousness) were compiled into a 34-item measure. Exploratory factor analysis was conducted on responses from 207 participants reporting profound experiences with ayahuasca (n=51), DMT (n=28), LSD (n=52), or psilocybin (n=76).Results: Factor analysis revealed a robust 6-factor structure: Dissolving of Identity (α=.94), Experiences of Eternity (α=.89), Dissolving of Physical Body (α=.80), Dissolving into Environment (α=.85), Clarity about Life and Purpose (α=.78), and Pleasure (α=.78). Two distinct substance clusters emerged: ayahuasca/DMT produced significantly higher dissolution scores than LSD/psilocybin across four factors, while all substances showed equivalent high scores on insight and pleasure dimensions. Dosage showed no significant effects.Conclusion: The MEDA provides preliminary evidence for multidimensional ego-dissolution assessment. Substance-specific clustering patterns might inform therapeutic selection, while universal insight and pleasure effects suggest core psychedelic benefits achievable across substances.