Longitudinal changes in recalled perceived life threat after a natural disaster.

Background: Post-traumatic stress disorder (PTSD) diagnosis often depends on a retrospective, self-report of exposure to a life-threatening event.

Aims: To examine the stability of recalled perceived life threat in a community sample exposed to a distinct stressful event.

Method: Five hundred and thirty-two Norwegian citizens who experienced the 2004 South-East Asia tsunami completed a self-report questionnaire 6 and 24 months post-disaster. The questionnaire measured perceived life-threat intensity, exposure, immediate stress response, psychopathology, personality dimensions, self-efficacy and social support.

Results: Recalled threat intensity increased from 6 to 24 months (P<0.001). Recall amplification was associated with lack of PTSD symptom improvement (P<0.05), but not with degree of exposure, immediate stress response, mood or stress symptoms, personality, self-efficacy or social support.

Conclusions: Recall amplification of perceived life threat from a single stressful event occurs in the general population, it may hinder PTSD symptom improvement and it questions the diagnostic validity of PTSD.