Longitudinal relationship between posttraumatic stress symptoms and physical symptoms in military veterans

Abstract

Objective: This study aimed to assess the temporal relationship of posttraumatic stress disorder (PTSD) symptoms and physical symptoms in a non–treatment-seeking deployed military sample. Methods: Data were from a longitudinal study of Australian Defence Force personnel deployed to the Middle East Area of Operations between 2010 and 2012 (n = 1871). Predeployment assessment was conducted 4 months before deployment (T1). Of these, 1324 (70.8% retention rate) participated in assessment within 4 months after deployment (T2), and 1122 (60.0%) completed the third time point at 4 years after deployment (T3). PTSD symptoms were assessed with the posttraumatic stress checklist and physical symptoms with a 67-item self-report Health Symptom Checklist. To explore directional influences between symptoms over time, longitudinal cross-lagged association between the modeled latent factors for PTSD symptoms and physical symptoms was estimated using structural equation modeling. Results: From T1 to T2, there was a significant bidirectional effect with higher physical symptom count at T1 predicting higher PTSD symptom severity at T2 (β = 0.17, p < .001) and higher PTSD symptom severity at T1 predicting higher physical symptom count at T2 (β = 0.13, p < .001). The effect of T2 on T3 was unidirectional. PTSD symptom severity at T2 had no effect on physical symptom count at T3, but physical symptom count at T2 predicted an increase in PTSD symptom severity at T3 (β = 0.11, p = .013). Conclusions: Considering early physical symptoms and their physiological underpinnings after traumatic exposures could help identify those at risk of later PTSD.