High cortisol awakening response in the aftermath of workplace violence exposure moderates the association between acute stress disorder symptoms and PTSD symptoms

Although a majority of people will be exposed to a traumatic event over the course of their lifespan, only a minority will develop post-traumatic stress disorder. Better understanding the factors contributing to the development of this psychopathology is of high importance and could significantly reduce the societal and human costs associated with PTSD. Acute stress disorder symptoms, which refers to clinical manifestations experienced in the aftermath of a traumatic event, have been shown to be associated with subsequent PTSD symptoms. Yet, many people who develop PTSD do not meet criteria for acute stress disorder in the first place, highlighting the need to refine the predictors of PTSD. The secretion of the stress hormone cortisol is dysregulated in PTSD patients. Whether combining clinical and biological measures in the aftermath of trauma could help to better explain subsequent PTSD symptoms remains to be tested. The current prospective study recruited 51 adults who were exposed to a traumatic event in their work setting, i.e. a psychiatric hospital. Acute stress disorder symptoms and cortisol awakening responses were assessed one to five weeks following trauma exposure (Time 1). PTSD symptoms were measured two months following trauma exposure. Results revealed a significant interaction between acute stress disorder symptoms and cortisol awakening response in predicting later PTSD symptoms. The results suggest that higher cortisol awakening response is a protective factor in that it abolishes the relationship between acute stress disorder symptoms and subsequent PTSD symptoms. These results point to the importance of considering multi-level information in the aftermath of trauma, such as clinical and biological measures, in order to better identify individuals who are at higher risk of developing PTSD.