Abstract: Interidentity amnesia is considered a hallmark of dissociative identity disorder (DID) in clinical practice. In this study, objective methods of testing episodic memory transfer between identities were used. Tests of both recall (interference paradigm) and recognition were used. A sample of 31 DID patients was included. Additionally, 50 control subjects participated, half functioning as normal controls and the other half simulating interidentity amnesia. Twenty-one patients subjectively reported complete one-way amnesia for the learning episode. However, objectively, neither recall nor recognition scores of patients were different from those of normal controls. It is suggested that clinical models of amnesia in DID may be specified to exclude episodic memory impairments for emotionally neutral material.

Ellert R. S. Nijenhuis, Richard van Dyck, ter Kuile MM, Mourits MJ, Philip Spinhoven, Onno van der Hart (2003)
Evidence for associations among somatoform dissociation, psychological dissociation and reported trauma in patients with chronic pelvic pain.
Psychosom Obstet Gynaecol. 2003 Jun;24(2):87-98.

Abstract: This study investigates somatoform as well as psychological dissociation, somatization and reported trauma among patients with chronic pelvic pain (CPP). Women with CPP (n = 52) who were newly referred to a gynecology department, or whose pain had resisted treatment, completed standardized self-report questionnaires and received a structured interview for DSM-IV dissociative disorders. The prevalence of dissociative disorders in the sample was very low. As hypothesized, self-reported somatoform dissociation was positively correlated with self-reported psychological dissociation and features of DSM-IV dissociative disorders; women who reported more serious psychic trauma, in particular sexual and physical abuse, experienced more somatoform and psychological dissociation than women reporting less trauma, or no trauma at all; and the association of somatoform dissociation and reported trauma was stronger than the association of psychological dissociation and trauma. Physical abuse/life threat posed by a person predicted somatoform dissociation best. The results are consistent with findings among psychiatric patients, and, therefore, strengthen the thesis that somatoform dissociation, (features of) dissociative disorder, and reported trauma are strongly intercorrelated phenomena.