Adding to the burden: the tendency to resonate with others' stress is linked to higher PTSD symptom severity in individuals with war-related trauma.

Many refugees experience multiple traumatic events, which set them at increased risk to develop post-traumatic stress disorder (PTSD). To refine interventions aimed at improving refugees' mental health, a better understanding of the factors modulating vulnerability to war-related trauma is needed. In the present study, we focused on stress resonance as a potential vulnerability factor. Stress resonance reflects the empathic sharing of others' subjective and physiological stress experience. Sixty-seven participants who came from Arabic-speaking countries and had entered Germany as refugees or migrants took part in an empathic stress test, in which they observed a native German speaker undergo a psychosocial laboratory stressor. Meanwhile, different stress markers (subjective stress, heart rate, heart rate variability, and cortisol release) were simultaneously captured in the stressed targets and passive observers. Moderation analyses did not support our hypothesis that the extent to which someone resonates with others' stress is a vulnerability factor in the development of PTSD symptoms after trauma exposure. Rather, higher levels of subjective and autonomic stress resonance were directly related to PTSD symptom severity when controlling for sex, age, and trauma exposure. Our findings suggest that heightened stress resonance may constitute a malleable correlate of PTSD symptoms rather than a trait modulating health risk. In the future, efforts should be made to test whether individuals with a history of war-related trauma would benefit from interventions aimed to reduce the tendency to excessively share others' stress.