Prevalence, Reliability and Validity of Dissociative Disorders in an Inpatient Setting

Abstract

The authors studied the prevalence and concurrent validity of the dissociative disorders in a private psychiatric hospital inpatient setting over a period of 8 months. All consenting patients admitted over a period of 8 months were administered the 8-item taxometric subscale of the Dissociative Experiences Scale (DES-T) and the Dissociative Disorders Interview Schedule (DDIS) by one interviewer. A second interviewer then administered the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D). Subsequently, a third interviewer conducted clinical diagnostic interviews on subjects positive and negative for dissociative disorders according to the previous interviewers. The second and third interviewers were blind to the results of the preceding interviews. A total of 407 individuals were admitted; of these, 201 completed the DES-T and DDIS; of these, 110 completed the SCID-D; and of these, 50 completed a clinical interview. The lifetime prevalences of dissociative disorders among the interviewed subjects were: DDIS, 40.8%; SCID-D, 44.5%; and clinician, 28.0%. The lifetime prevalences of dissociative identity disorder were: DDIS, 7.5%; SCID-D, 9.1%; and clinician, 10.0%. Kappas for presence of dissociative identity disorder or dissociative disorder not otherwise specified versus no dissociative disorder were: DDIS-DES-T, 0.81; SCID-D-DES-T, 0.76; clinician-DES-T, 0.74; DDIS-SCID-D, 0.74; DDIS-clinician, 0.71; and SCID-D-clinician, 0.56. Kappas for dissociative amnesia and depersonalization disorder were not significant. Dissociative disorders, including dissociative identity disorder, are common in inpatient settings. Chronic, complex dissociative disorders have good concurrent validity. Dissociative fugue is too rare for reliability data to be accumulated. Dissociative amnesia and depersonalization disorder did not demonstrate validity in this study.