Dissociation as a Distinct Peritraumatic Coping Response: A Preliminary Analysis.

Research examining physiological responses to trauma cues in PTSD has identified a subset of "nonresponders" showing suppressed physiological reactivity. The defense cascade model posits that individuals respond to stressors by progressing through a series of defensive reactions, with nonresponders having advanced to a shutdown response. It remains unclear whether dissociation is at the end of a continuum of passive behavior, indicating full shutdown, or if it comprises a distinct response. The present study aimed to address this uncertainty, using EFA to compare a two-factor (active, passive) and three-factor (active, passive, dissociative) model of defensive responding. Eighty-nine female physical and sexual assault survivors reported their peritraumatic reactions within 1 month of their assault, which were entered into the EFA. The three-factor model was superior, suggesting dissociation is a distinct category of peritraumatic coping. Peritraumatic use of both passive and dissociative coping strategies were each significantly associated with ongoing use of passive coping and increased PTSD symptoms 1-month posttrauma; surprisingly, the use of passive peritraumatic coping strategies was a better indicator than peritraumatic dissociation. The inclusion of depression as a covariate removed the association of passive (but not dissociative) coping with PTSD symptom severity. Active coping use was not significantly associated with any outcome, suggesting that the presence of shutdown responses is more informative than the presence or absence of any active coping. These findings highlight the importance of differentiating peritraumatic coping responses and the need for increased attention to the comparatively neglected topic of passive coping.

Prospectively predicting PTSD status with heart rate reactivity and recovery in interpersonal violence survivors.

The current study used heart rate (HR) reactivity to personalized trauma cues and HR recovery to predict later Posttraumatic Stress Disorder (PTSD) status in female interpersonal violence survivors. A scripted imagery paradigm was used to assess initial (M = 1 month posttrauma) HR reactivity during exposure to and recovery following idiographic trauma cues. In addition, follow-up PTSD status (M = 8 months posttrauma) was assessed with the Clinician Administered PTSD scale (CAPS). A logistic regression was used to predict PTSD status at the follow-up assessment with HR reactivity during exposure to a personalized trauma audio script and recovery periods at initial assessment entered hierarchically. Script HR reactivity alone did not significantly predict PTSD status. However, after adding HR recovery, the model was significant. Higher HR during recovery was significantly positively associated with PTSD-positive status while script HR reactivity remained a non-significant predictor. The model correctly classified 70% of cases with PTSD. A second logistic regression with initial CAPS severity as a covariate showed that HR recovery added predictive value beyond acute PTSD symptoms. These results suggest that HR recovery following trauma cue exposure is an important predictor of PTSD development.