Neuropsychological differences in Dissociative and non-Dissociative Post-traumatic Stress Disorder (PTSD) patients.

Proposal details

Title: Neuropsychological differences in Dissociative and non-Dissociative Post-traumatic Stress Disorder (PTSD) patients.
Research Area(s): PTSD and other Anxiety Disorders
Background: Post-traumatic stress disorder (PTSD) is a psychiatric condition triggered by exposure to a distressing traumatic event with symptoms that include re-experiencing, avoidance and hyper-arousal to threat stimuli (Pole, 2007). Neuropsychological studies in PTSD typically report deficit in attention, working memory and verbal function. However, neuropsychological findings have been mixed and inconsistent. A potential explanation for these mixed findings is sample heterogeneity and under-researched sub-types of PTSD. The study will attempt to identify neuropsychological impairments associated with two important sub-groups of PTSD, those who report dissociative and non-dissociative reactions according to the Clinician Administered Dissociative States Scale (CADDS). Dissociation comprises a disruption in the usually integrated functions of perception, memory, and emotional reactions (American Psychiatric Association, 1994). It can result in perceptual alterations, emotional numbing, depersonalisation or emotional detachment from one’s environment (Bryant, 2007). These responses may serve as a protective function that may subsequently impair memory (Horowitz, 1986). To date, the neuropsychological effects of PTSD, particularly memory and attention, have been largely studied without the consideration of these sub-groups. Because neurophysiological symptoms and severity differ in these two sub-groups, it is worthwhile studying their neuropsychological differences separately. Doing this may provide new insights into developing more specific methods of treating the disease.
Aims: Our initial aim is to explore neuropsychological differences between PTSD patients with dissociative and non-dissociative reactions and healthy controls that may account for some variability in literature findings. Secondly, we aim to explore the correlations between dissociation and neuropsychological function in PTSD. The hypothesis is that (1) dissociation will be associated with a significant impairment of memory and attention function. This will be reflected in impaired attention and memory test results for dissociative PTSD compared to both non-dissociative PTSD and healthy controls, and in negative correlations between CADDS scores and attention and memory function.
Method: PTSD patients with dissociation (CADDS score of > 15), PTSD patients without dissociation (CADDS score of