Testing the dimensionality of posttraumatic stress responses in young Chinese adult earthquake survivors: further evidence for "dysphoric arousal" as a unique PTSD construct.

BACKGROUND This study investigated an alternative five-factor diagnostic model for posttraumatic stress disorder (PTSD) symptoms, and tested external convergent and discriminant validity of the model in a young Chinese sample of earthquake survivors. METHODS A total of 938 participants (456 women, 482 men) aged 15-20 years were recruited from a vocational school originally located in Beichuan County Town which was almost completely destroyed by the "Wenchuan Earthquake." The participants were administrated with the PTSD Checklist and the Hopkins Symptoms Checklist-25 12 months after the earthquake. RESULTS The results of confirmatory factor analysis showed that the five-factor intercorrelated model (intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal) fit the data significantly better than the four-factor numbing model proposed by King et al. (1998: Psychol Assess 10:90-96) and the four-factor dysphoria model proposed by Simms et al. (2002: J Abnorm Psychol 111:637-647). Further analyses indicated that four out of five PTSD factors yielded significantly different correlations with external measures of anxiety versus depression. CONCLUSIONS The findings provide further empirical evidence in favor of the five-factor diagnostic model of PTSD, and carry implications for the upcoming DSM-5.