Psychometric validation of the French version of the five-dimensional altered states of consciousness questionnaire (5D-ASC) and associated 11 OAV subscales.
Progress in neuro-psychopharmacology & biological psychiatry June 20, 2026 Ewen Kervadec, Pauline Mathieu, Baptiste Fauvel et al.
A French translation of the Altered States of Consciousness (5D-ASC) questionnaire was psychometrically validated using data from 777 participants who recalled a past naturalistic psychedelic experience. The 11-subscale structure showed better fit than higher-order models, though fit indices fell slightly below conventional thresholds. Internal consistency was excellent for global scores (α = 0.95) and satisfactory across subscales (α = 0.63–0.84). Measurement invariance across substance categories was confirmed, with latent factor differences aligning with known pharmacological profiles. The findings provide preliminary evidence supporting the French 5D-ASC's validity, enabling francophone research linking subjective experience to therapeutic outcomes.