Background: Severe traumatic stressors such as war, rape, or life-threatening accidents can result in a debilitating psychopathological development conceptualised as Posttraumatic Stress Disorder (PTSD). Pathological memory formation during an alarm response may set the precondition for PTSD to occur. If true, a lack of memory formation by extended unconsciousness in the course of the traumatic experience should preclude PTSD.
Methods: 46 patients from a neurological rehabilitation clinic were examined by means of questionnaires and structured clinical interviews. All patients had suffered a TBI due to an accident, but varied with respect to falling unconscious during the traumatic event.
Results: 27% of the sub-sample who were not unconscious for an extended period but only 3% (1 of 31 patients) who were unconscious for more than 12 hours as a result of the accident were diagnosed as having current PTSD (P <.02). Furthermore, intrusive memories proved to be far more frequent in patients who had not been unconscious. This was also the case for other re-experiencing symptoms and for psychological distress and physiological reactivity to reminders of the traumatic event.
Conclusion: TBI and PTSD are not mutually exclusive. However, victims of accidents are unlikely to develop a PTSD if the impact to the head had resulted in an extended period of unconsciousness.