Ridgeview Institute and the International Society for the Study of Multiple Personality and Dissociation
Abstract
p. 151-153The purpose of the present study was to provide further evidence in support of the validity of the Dissociative Experiences Scale (DES) as a reliable measure of dissociative psychopathology. The DES was administered to 259 college students, 33 patients with multiple personality disorder (MPD), and 29 patients with a dissociative disorder not otherwise specified (DDNOS). The inter-rater reliability for the DES scoring procedure was excellent (coefficient of absolute agreement=.96; coefficient of relative agreement =.99). The test retest reliability of DES scores (within approximately one month) was also excellent (coefficient of absolute agreement =.93; coefficient of relative agreement=.96) and suggests that DES total scores are temporally stable and similar in absolute value across testings. Finally, the internal consistency of DES scores was also very high (alpha for students=.93; alpha for MPD patients =.94; alpha for DDNOS patients=.94; alpha for the combined total sample=.95). Both MPD (mean DES score =55.0) and DDNOS patients (mean DES score =40.8) earned significantly higher DES scores than students (mean DES score=23.8). In addition, MPD patients earned significantly higher DES scores than DDNOS patients. The results of the present study also suggest that a DES cutoff score of 45 to 55 maximizes the probability of correctly classifying students from dissociative disorder patients (87%) while minimizing the rates of false positive (2 to 6 %) and false negative errors (7 to 11%). Suggestions for further validation research are also made
