Although the majority of people who are exposed to traumatic events do not develop psychopathology, trauma has often been associated with increased vulnerability to psychiatric disorders. In addition, alterations in the HPA-axis have been demonstrated in patients with trauma-related psychiatric disorders. We hypothesize that trauma causes dysregulation of the HPA-axis. Therefore, we will compare HPA-axis functioning of traumatized and non-traumatized healthy individuals from the same gender and age from two categories: military and railroad personnel. In addition, a group of women with a history of childhood trauma was included. We will investigate for the putative role of attachment style and psychological resilience factors such as coping. In this article, we present the rationale for this study.