The Fear Response in Dissociative Identity Disorder: a Fear Potentiated Startle Study.
- The overgeneralization of conditioned fear and the impaired ability to extinguish fear are potential mechanisms underlying alterations in arousal associated with trauma-spectrum disorders. Classic posttraumatic stress disorder (PTSD) is associated with an exaggerated acoustic startle response (ASR) and a failure to extinguish the fear response in a fear-potentiated startle (FPS) paradigm. Dissocia... read moretive identity disorder (DID), a trauma-spectrum disorder linked with chronic childhood abuse and trauma, presents hallmark symptoms including derealization, depersonalization, and intrusive thoughts, which contrast some of the arousal-based symptoms of PTSD. To date, one study has examined ASR and pathological dissociation and found that dissociative experiences in individuals with borderline personality disorder were linked with an attenuated ASR (Ebner-Premier, 2005). We aimed to replicate and extend these findings in an ongoing study of women with histories of childhood abuse and a diagnosis of DID (N = 12; age M = 45.58). Participants completed a self-report battery, reporting high levels of arousal-based symptoms and pathological dissociation, and an FPS paradigm measuring facial electromyography (EMG), heart rate, and skin conductance. Based on button-box responses recorded during the experiment, we found that participants successfully learned to discriminate between the danger and the safety signals. Participants also displayed lower overall FPS compared to what is seen in the literature for both non-clinical and PTSD patients, though levels of pathological dissociation were correlated with greater FPS. This could indicate that increased DID symptomology is associated with severe comorbid PTSD symptoms, while dissociation in general correlates with a dampened autonomic response. Our findings will help provide a basic understanding of the fear response in DID, informing treatment development to manage physiological symptoms.read less