Dissociative episodes and concurrent heart rate in patients with PTSD - An ecological momentary assessment

Dissociative symptoms are a frequent complication in posttraumatic stress disorders affecting about a third of all PTSD patients. While theoretical models predict a physiological hypoarousal during posttraumatic dissociations, empirical evidence is lacking. We addressed this by studying spontaneously occurring dissociative symptoms and related heart rate changes in an ecological momentary assessment. Therefore, we continuously measured heart rate for five to ten days with mobile ECG in 47 female inpatients diagnosed with posttraumatic stress disorder and dissociative symptoms. During this observation period, patients tracked each dissociative event on a smartphone app and reported on symptom characteristics. Patients reported a total of 164 dissociative events. Those typically lasted <30 min and involved co-occuring depersonalization and derealization of moderate to severe intensity. Tracked symptoms correlated positively with some conventional self-reports for depersonalization and derealization. Heart rate during dissociative symptoms varied greatly between and within individuals and was on average not different from baseline assessment. There was also no significant relation between dissociation intensity and heart rate change. These results challenge the theory of reactive hypoarousal during chronic dissociation and support the view that physiological adaptation modifies in the course of posttraumatic chronification. They also highlight the individual variability of dissociative symptoms and underscore the necessity of detailed assessment for targeted therapeutic approaches.