Delayed-onset posttraumatic stress disorder: a prospective evaluation


  • School of Psychology, University of New South Wales, New South Wales 2052, Australia. Email:

    Allison G. Harvey, Lecturer

    University of Oxford, Oxford, United Kingdom

Richard A. Bryant, Associate Professor, (Correspondence)


Objective: 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.

Method: 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.

Results: Five patients displayed PTSD 2 years post-trauma without meeting PTSD criteria 6 months posttrauma. Delayed onset cases were characterized by elevated psycho­pathology scores and resting heart rate levels within the initial month and elevated psychopathology 6 months posttrauma.

Conclusions: 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.