Phenomenological assessment of psychedelic induced experiences: Translation and validation of the German Challenging Experience Questionnaire (CEQ) and Ego-Dissolution Inventory (EDI)
Katharina Dworatzyk, Tallulah Jansen, Timo Torsten Schmidt
April 2, 2021 preprint DOI: 10.31234/osf.io/kxmgq (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional psychometric validation study |
|---|---|
| Population | German-speaking adults with psychedelic experiences |
| Topics | Anxiety Ego dissolution |
| Keywords | Confirmatory factor analysis Exploratory factor analysis Construct validity Clinical psychology Nomological network Convergent validity German Scale ratio Psychometrics Internal consistency Structural equation modeling Statistics |
| Citations | 3 |
| Key findings | The German Challenging Experience Questionnaire showed good psychometric properties, while the German Ego-Dissolution Inventory required a revised five-item structure for adequate validity. |
Abstract
Several measures have been designed to assess subjective experiences induced by psychedelic substances and other mind-altering drugs or non-pharmacological methods. Recently, two self-report questionnaires have been introduced to measure acute adverse effects following psilocybin ingestion and the phenomenon of ego-dissolution associated with psychedelic use, respectively. The 26-item Challenging Experience Questionnaire assesses multiple dimensions of psilocybin induced experiences, whereas the 8-item Ego-Dissolution Inventory consists of a uni-dimensional scale. In the present study, these questionnaires were translated into German and their psychometric properties then evaluated in an online survey on psychedelic induced experiences. Confirmatory factor analysis confirmed the 7-factor structure of the German Challenging Experience Questionnaire with overall good internal consistency for all subscales. The factor structure did not differ based on gender or prior struggle with anxiety or depression, furthering the evidence of internal validity. Correlations with the State-Trait-Anxiety Inventory and the Altered States of Consciousness Rating Scale demonstrated convergent validity. Confirmatory factor analysis did not confirm the hypothesized single-factor structure of the German Ego-Dissolution Inventory and exploratory factor analysis suggested an alternative factor structure, where only five items loaded onto a common factor that was interpreted as ego-dissolution. Internal consistency of this 5-item measure was high and correlation with selected items of the Mystical Experience Questionnaire and Altered States of Consciousness Rating Scale supported convergent validity. Translation and validation of these questionnaires contribute to the advancement of common standards in the psychological and neuroscientific study of altered states of consciousness.
Comparable studies
Other cross-sectional and survey studies on ego dissolution, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Naturalistic use of psychedelics is related to emotional reactivity and self-consciousness: The mediating role of ego-dissolution and mystical experiences Adults with varying histories of psychoactive substance use, including 1661... | 2022 | Cross-sectional survey | n = 2,516 |
| Linkages between Psychedelics and Meditation in a Population-Based Sample in the United States. American adults | 2023 | Cross-sectional survey | n = 953 |
| Losing the Self in Near-Death Experiences: The Experience of Ego-Dissolution. Near-death experiencers with NDE-C scale total score ≥27/80 | 2021 | Survey | n = 100 |
| Cross-validation of the ego dissolution scale: implications for studying psychedelics. Adults recruited online | 2023 | Cross-sectional validation study | n = 527 |
| Embracing change: impermanence acceptance mediates differences in death processing between long-term ayahuasca users and non-users. Ayahuasca veterans and non-users | 2025 | Cross-sectional study | n = 107 |
Citations in the library
Cited by 3
- The Acceptance/Avoidance-Promoting Experiences Questionnaire (APEQ): A theory-based approach to psychedelic drugs’ effects on psychological flexibility Journal of Psychopharmacology March 1, 2022
- Adaptation and latent structure of the Brazilian version of the Ego Dissolution Inventory (EDI-BR): an exploratory study Trends in Psychiatry and Psychotherapy October 18, 2022
- Therapeutic-Like Context and Relational Support During Psychedelic Use Moderate Links Among Stress, Challenging Experiences, and Psychological Outcomes. Journal of Psychoactive Drugs March 14, 2026
Cites 12
- Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV) PLoS One August 31, 2010
- Altered States of Consciousness Archives of General Psychiatry September 1, 1966
- Validation of the revised Mystical Experience Questionnaire in experimental sessions with psilocybin Journal of Psychopharmacology October 6, 2015
- Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution. Current Biology April 13, 2016
- Ego-Dissolution and Psychedelics: Validation of the Ego-Dissolution Inventory (EDI) Frontiers in Human Neuroscience June 14, 2016
and 7 more in the library