The course of dissociation for patients with borderline personality disorder and axis II comparison subjects: a 10-year follow-up study

Objective: The purpose of this study was to assess the severity of dissociation reported by borderline patients and axis II comparison subjects over 10 years of prospective follow‐up. Method: The Dissociative Experiences Scale (DES) – a 28‐item self‐report measure – was administered to 290 borderline in‐patients and 72 axis II comparison subjects during their index admission. It was also re‐administered at five contiguous 2‐year follow‐up periods. Results: The overall severity of dissociative experiences of those in both study groups decreased significantly over time but was discernibly greater in borderline patients (61% vs. 43%). The same pattern emerged for the subtypes of dissociation that were studied: absorption, depersonalization and amnesia. Conclusion: The severity of dissociation declines significantly over time for even severely ill borderline patients. However, it remains as a recurring problem for over a third of those with DES scores that initially were in the range associated with trauma‐spectrum disorders.