Abstract
Objective: This study aims to determine whether symptoms of post-traumatic stress disorder (PTSD) form a latent dimension reflecting responsivity to life events and whether PTSD symptoms are specific to traumatic life events. Method: A 30-year longitudinal study of a general population sample of 987 individuals were assessed for PTSD symptoms, exposure to adverse life events, and a variety of psychosocial measures. PTSD symptoms were tested using a confirmatory factor model and a range of fitted models were used to identify significant predictors of latent PTSD symptoms. Results: The rate of DSM IV PTSD was 1.9%. However, subjects reported high rates of at least one significant traumatic or negative life event and PTSD symptoms. The PTSD symptoms conformed well to a single latent factor. There were strong linear associations between severity of PTSD symptoms and exposure to traumatic and non-traumatic life events. Factors contributing to latent PTSD symptoms were gender, childhood anxiety, neuroticism, self-esteem, and quality of parental care. Conclusion: Criteria for PTSD form an underlying dimension reflecting the individual's level of responsivity to traumatic and non-traumatic stressful life events. PTSD symptoms form a continuum of severity with minor stress symptoms at one end and severe PTSD at the other.