Validity and reliability of a Persian version of the Dissociative Experiences Scale II (DES-II) on Iranian patients diagnosed with schizophrenia and mood disorders

ABSTRACT

Dissociative Experiences Scale (DES) is a valid self-reported tool to evaluate both non-pathological and pathological dissociative experiences. This study aims at evaluating the psychometric properties of a Persian version of the DES-II on both non-clinical samples and patients with schizophrenia and mood disorders. The back-translated DES-II was administered to 370 individuals being divided into three groups (270 healthy subjects, 50 patients with mood disorders, and 50 patients with schizophrenia) recruited from Shahid Beheshti Hospital of Kerman Medical University. The results showed a good reliability (Cronbach’s alpha = 0.95), a very high item-total correlation, and a good internal consistency of 0.892 measured by split half. Moreover, the Persian version of the DES-II questionnaire demonstrated convergent validity of the scale. Analyses of the DES-II subscales revealed significant differences for amnesic experiences, absorption/imaginative involvement, and depersonalization/derealization among healthy individuals, and patients with mood disorders as well as schizophrenia. We also found significant differences among only schizophrenia group but not mood disorders group in comparison with healthy individuals (p value = .0001, and 0.70, respectively), and between patients with schizophrenia and patients with mood disorders (p value = .03) using DES-T. As a conclusion, the Persian version of the DES-II is an appropriate, reliable, and valid tool to screen dissociative experiences and discriminate subcomponents of dissociative disorders in the Iranian population.