The measurement of dissociation in normal and clinical populations: Meta-analytic validation of the Dissociative Experiences Scale (DES)

The Dissociative Experiences Scale (DES) has now been used in over 100 studies on dissociation. This article reports on a series of meta-analyses to test some of the theoretical assumptions underlying the DES and to examine the instrument's reliability and validity. Studies with the DES were identified through Psychlit, Medline, Social Sciences Citation Index, and Current Contents. Across studies in similar domains (e.g., studies on multiple personality disorders) combined effect sizes were computed using the Rosenthal-Mullen approach. The DES showed excellent convergent validity with other dissociative experiences questionnaires and interview schedules (combined effect size: d = 1.82; N = 5, 916). The DES also showed impressive predictive validity, in particular concerning dissociative disorders (Multiple Personality Disorder: combined effect size d = 1.05; N = 1, 705) and traumatic experiences (post-traumatic stress disorder: combined effect size d = 0.75; N = 1,099; and abuse: combined effect size d = 0.52; N = 2,108). However the discriminant validity was less well established. The DES is sensitive to response and experimenter biases. It is recommended to average DES-scores over more points in time and over more judges. The DES seems to measure the current view on past dissociative experiences. The model of dissociation as a form of autohypnosis failed to receive support from the data. A developmental model to interpret dissociation is proposed.