Delayed-onset posttraumatic stress disorder: a prospective evaluation.

Delayed onset posttraumatic stress disorder (PTSD) refers to PTSD that develops at least 6 months after the traumatic event. This study aimed to index the features of patients who develop delayed-onset PTSD. This study investigated delayed onset PTSD by prospectively assessing 103 motor vehicle accident survivors within 1 month of the motor vehicle accident for acute stress disorder, and subsequently assessing them for PTSD 6 months post-accident, and 2 years post-accident. Patients were initially assessed for symptoms of traumatic stress, anxiety, depression, and resting heart rate. Five patients displayed PTSD 2 years post-trauma without meeting PTSD criteria 6 months posttrauma. Delayed onset cases were characterized by elevated psycho-pathology scores and resting heart rate levels within the initial month and elevated psychopathology 6 months posttrauma. These findings suggest that cases of delayed onset PTSD suffer subsyndromal levels of posttraumatic stress prior to the diagnosis of PTSD. These findings challenge the notion of PTSD developing after a period without symptoms.