Neuroimaging-DID

Dissociative identity disorder (DID) is probably the most disputed psychiatric diagnosis. In fact, since its official recognition in the DSM IV, supporters of the diametrically opposed iatrogenic and traumagenic views have been engaged in passionate debate. The iatrogenic proponents assert that DID originates from (possibly suggestive) psychotherapeutic treatment and the creation of false memories. Traumagenic proponents hold that DID constitutes a severe form of post-traumatic stress disorder (PTSD).

According to the DSM-IV, DID is characterised by, among others, a disruption in consciousness and the presence of two or more distinct identities or personality states. Each of these states has its own perception of, relating to, and thinking about the environment and the self. Within the traumagenic view, DID is believed to originate from a self-protecting reaction in order to cope with chronic, severe trauma, such as persistent abuse. As a result of this coping strategy different types of identity states can be developed, e.g. neutral identity states (NIS) and trauma-related emotional states (TIS). In a NIS, DID patients concentrate on functioning in daily life. To that end, NIS has amnesia for traumatic memories, thereby disabling recognition of trauma-related information. In contrast, the TIS does have conscious access to the traumatic memories.

To date, research examining amnesia in DID has produced conflicting results. Specifically testing inter-identity amnesia using psychological tests, for example, did not yield evidence for inter-identity amnesia in DID patients for newly learned non-autobiographical information even though this was subjectively reported by the DID patients. These findings are in favor of the iatrogenic view. In contrast, the results of a pioneering functional neuroimaging study using positron emission tomography (PET) are in line with the traumagenic position and subjective reports (see reference under the section 'people'). In this study differences were found between NIS and TIS in subjective reactions, cardiovascular responses and cerebral activation patterns when exposed to autobiographical trauma-related information.

How can we reconcile these apparent differences? That is exactly the topic of this research project. This research project aims, by using state-of-the-art brain imaging techniques, to assess the etiology of DID in a design that acknowledges both the iatrogenic and traumagenic view. Furthermore, this research aims to identify differences and/or similarities in functional brain mechanisms and anatomical structure between patients with DID and several control groups. The integrative information of multi-modal brain imaging techniques will generate a broad range of solid information about the interaction of brain function and anatomy in DID. Results will inform both holders of the traumagenic and iatrogenic view about the etiology of DID. In addition, results can offer information to psychotherapists and thereby contribute to a consensus on the diagnosis and therapy of DID. This project has emerged from a neuroscientific interest, but is in collaboration with experts in the clinical field (see also here).

Background