DES-II

The Dissociative Experiences Scale-II (DES-II) is a 28-item self-report questionnaire measuring the frequency of dissociative experiences such as absorption, depersonalization, derealization, and amnesia. Respondents indicate the percentage of time (0–100%) they experience each item, and the overall score is the mean across all items. Developed by Eve Bernstein Carlson and Frank Putnam, the DES-II is the most widely used screening instrument for dissociative disorders. A mean score above 30 is generally considered indicative of a dissociative disorder. In psychedelic research, the DES-II is used to screen participants (high dissociation often being exclusionary) and to monitor dissociative experiences during or after psychedelic sessions. The scale has good test–retest reliability (r ≈ 0.79–0.84) and high internal consistency (α ≈ 0.93).