An investigation of the Ehlers-Clark cognitive theory of PTSD and the phenomenon of mental pollution

Cognitive models have successfully added to our understanding of the onset and maintenance of many anxiety disorders. I tested one component of a recent cognitive model of posttraumatic stress disorder (Ehlers & Clark, 2000) and examined the related phenomenon of mental pollution in a sample of 50 female sexual assault victims. Results indicated that sexual assault appraisals were strongly and positively related to PTSD symptoms. These relations remained significant after statistically controlling for the severity of the assault. Appraisals of the sexual assault and its sequelae explained a significant amount of the variance in PTSD symptoms even after the variance attributable to sexual assault severity was accounted for. Sixty percent of the women interviewed reported some feelings of mental pollution subsequent to the assault. Feelings of mental pollution related to post-assault washing behaviour. Deliberate recall of the assault resulted in stronger feelings of dirtiness and the urge to wash than deliberate attention to a pleasant memory or scene. In response to deliberate recall of the assault memory, nine women reported washing their hands. These findings support the cognitive model of PTSD proposed by Ehlers and Clark, and suggest that the phenomenon of mental pollution is important to our understanding of sexual assault trauma.