Inter-identity amnesia for neutral episodic self-referential and autobiographical memory in Dissociative Identity Disorder: An assessment of recall and recognition.

Amnesia is a core diagnostic criterion for Dissociative Identity Disorder (DID), however previous research has indicated memory transfer. As DID has been conceptualised as being a disorder of distinct identities, in this experiment, behavioral tasks were used to assess the nature of amnesia for episodic 1) self-referential and 2) autobiographical memories across identities. Nineteen DID participants, 16 DID simulators, 21 partial information, and 20 full information comparison participants from the general population were recruited. In the first study, participants were presented with two vignettes (DID and simulator participants received one in each of two identities) and asked to imagine themselves in the situations outlined. The second study used a similar methodology but with tasks assessing autobiographical experience. Subjectively, all DID participants reported amnesia for events that occurred in the other identity. On free recall and recognition tasks they presented a memory profile of amnesia similar to simulators instructed to feign amnesia and partial information comparisons. Yet, on tests of recognition, DID participants recognized significantly more of the event that occurred in another identity than simulator and partial information comparisons. As such, results indicate that the DID performance profile was not accounted for by true or feigned amnesia, lending support to the idea that reported amnesia may be more of a perceived than actual memory impairment.

The Detachment and Compartmentalization Inventory (DCI): An assessment tool for two potentially distinct forms of dissociation.

While evidence suggests a division between two qualitatively distinct forms of dissociation, no scale has been specifically designed to differentiate between them. This study describes the development and validation of the Detachment and Compartmentalization Inventory (DCI). The DCI was developed from dissociation theory, 29 existing dissociation scales and expert opinion. An initial pilot study was conducted which assessed readability, explored validity and reduced items before the DCI was administered online to 89 nonclinical and 105 clinical participants. The Dissociative Experiences Scale (DES), Somatoform Dissociation Questionnaire (SDQ), and Mindfulness Attention Awareness Scale (MAAS) were included in the survey battery. The DCI exhibited good internal reliability, discriminant validity, convergent validity, construct validity and concurrent validity. The final version containing 22-items, is self-administered, grounded in the theoretical literature and supported by initial psychometric evaluation. It has 10 items assessing compartmentalization, 10 items assessing detachment and two items examining valid responding. The DCI could detect compartmentalization and detachment, and was designed for clinical research and for screening patients.