Decreased awakening cortisol over the course of humanitarian aid deployment is associated with stress-related symptoms: A prospective cohort study

Abstract

Background: Internationally deployed humanitarian aid (HA) workers are at risk for traumatic and chronic stress, and consequently stress-related psychopathology. Therefore, HA deployment may lead to long-term changes in neuroendocrine stress reactivity. Objective: We investigated whether awakening cortisol changed upon deployment, and whether this was associated with lifetime childhood and adulthood traumatic stressors, current deployment-related traumatic and chronic stressors and within-person changes in stress-related symptomatology upon deployment. Method: From a prospective study among expatriate HA workers (n = 214) from 19 international NGOs, we included n = 86 participants (68% females, 33 ± 8 years) who completed questionnaires and cortisol assessments at three points: pre-deployment, early post-deployment and 3–6 months post-deployment. At each assessment, cortisol parameters were calculated from two saliva samples: at awakening and 30 minutes post-awakening. Results: Linear mixed models showed significant decreased awakening cortisol over time (bs: −.036 [SE = .011] to −.008 [SE = .003], all ps < .007). Cortisol was significantly predicted by three-way interactions between lifetime stressors, deployment stressors and time, with the smallest decrease over time in those with limited lifetime and current stressors (all ps < .05). The change in cortisol was no longer significant upon inclusion of stress-related symptoms in the model. Moreover, a sharper cortisol decrease was significantly associated with higher anxiety (p = .004) and PTSD symptoms (p = .049) across assessments. Conclusions: This is the first study indicating decreased awakening cortisol after HA deployment. The exact decrease within participants depended on the amount of lifetime and current stressors. Importantly, when taking changes in stress-related symptomatology into account, we found these accounted for the attenuated awakening cortisol.