Dissociation and post-traumatic stress disorder: two prospective studies of road traffic accident survivors

Background Dissociative symptoms during trauma predict post-traumatic stress disorder (PTSD), but they are often transient, It is controversial whether they predict chronic PTSD over and above what can be predicted from other post-trauma symptoms. Aims To investigate prospectively the relationship between dissociative symptoms before, during and after a trauma and other psychological predictors, and chronic PTSD. Method Two samples of 27 and 176 road traffic accident survivors were recruited. Patients were assessed shortly after the accident and followed at intervals over the next 6 months. Assessments included measures of dissociation, memory fragmentation, data-driven processing, rumination and PTSD symptoms. Results All measures of dissociation, particularly persistent dissociation 4 weeks after the accident, predicted chronic PTSD severity at 6 months. Dissociative symptoms predicted subsequent PTSD over and above the other PTSD symptom clusters. Memory fragmentation and data-driven processing also predicted PTSD, Rumination about the accident was among the strongest predictors of subsequent PTSD symptoms. Conclusions Persistent dissociation and rumination 4 weeks after trauma are more useful in identifying those patients who are likely to develop chronic PTSD than initial reactions. Declaration of interest None.