| Objective Assessment of Peritraumatic
Dissociation: Psychophysiological Indicators
Priscilla Schulz, LCSW
from an article of the same title by:
Michael G. Griffin, Patricia A. Resick, and Mindy B. Mechanic, University of Missouri - St. Louis
American Journal of Psychiatry, V. 154 (8),
What is dissociation?
Dissociation refers to the experience in which a person's normal awareness, memory, identity or perception of the environment is temporarily disrupted. It may include:
Numerous studies in the last decade have noted a relationship between dissociation during a traumatic event (peritraumatic dissociation) and the later development of posttraumatic stress disorder (PTSD). A 1993 study of disaster survivors found that survivors' self-reports of dissociation during the disaster were a significant predictor of later PTSD. In addition, one study of combat
veterans found that both peritraumatic dissociation and current dissociation among combat veterans improved predictions of current PTSD more than veterans' levels of exposure to war zone stress. Researchers theorize that whereas peritraumatic dissociation may be adaptive during a traumatic event, subsequent use of this mechanism for coping with feelings of distress when reminded of the trauma may lead to survivors' failure to process the trauma, both its meaning and the emotions associated with the experience. Ultimately this may result in the development of more severe posttrauma reactions or PTSD.
What is the purpose of this study?
The main purpose of this study is to objectively measure and assess peritraumatic dissociation and its relationship to PTSD soon after a traumatic event. By doing this, it hopes to fill a gap in the body of knowledge about dissociation and PTSD. In addition it hopes to shed light on the issue of whether there are specific components of posttrauma pathology that inhibit trauma recovery and lead to PTSD. The study's second aim is to improve upon existing self-report measures of dissociation and trauma pathology by comparing responses with objective data in the form of subjects' physiological responses.
Study participants were all recent rape survivors who entered the study within two weeks of the assault. Heart rate and two types of skin conductance responses (similar to what is used in lie-detector tests) were measured while the rape survivors talked about the rape. Self-reports and interview measures of psychopathology and dissociation were also collected on study participants. Care was taken to determine which study participants had dissociated during the rape and those who had not. This was done to assure that comparisons were made between a group who clearly dissociated and a group who clearly had not. Because survivors were assessed only two weeks after the trauma, a diagnosis of PTSD, by definition, was not possible (PTSD symptoms must persist at least one month to be diagnosed as posttraumatic stress disorder); subjects were diagnosed as having or not having symptoms characteristic of PTSD.
What are the study's findings?
Researchers admit that they do not know why high dissociators' expressed distress was incongruent with physiological measures of distress. High dissociators scored higher on measures of depression than low dissociators. Whether depressive symptoms could account for suppressed physiological responses to retelling the rape is not known, but previous research with combat veterans does not support this idea. It is also unclear if high dissociators expressed distress because they believed it was more socially acceptable to say they were upset than to admit feeling nothing or numb when talking about the rape.
Reviewed by Priscilla Schulz, September 1999