EDI

The Ego Dissolution Inventory (EDI) is an 8-item self-report measure developed by Matthew Nour and Robin Carhart-Harris at Imperial College London to specifically quantify the experience of ego dissolution during psychedelic states. Ego dissolution — the subjective loss of the sense of self and its boundaries — is considered a core phenomenological feature of high-dose psychedelic experiences and has been linked to therapeutic outcomes. Each item is rated on a 0–100 visual analog scale, and the mean score is taken. The EDI was validated using data from a large online survey of psychedelic users and correlates strongly with the Oceanic Boundlessness dimension of the 5D-ASC. It also includes an 8-item Ego Inflation subscale measuring experiences of grandiosity and heightened self-assuredness. The EDI provides a targeted, efficient measure of a specific experiential dimension increasingly recognized as mechanistically important in psychedelic therapy.