Infidelity is often conceptualized as a traumatic event; however, little research has explored this topic empirically, particularly in unmarried adults. We determined the prevalence of infidelity-related post-traumatic stress disorder (PTSD) symptoms among unmarried adults who experienced a partner's infidelity and whether probable infidelity-related PTSD was associated with additional psychological health outcomes (i.e., depressive symptoms, perceived stress, and anxiety symptoms). We also investigated whether negative post-traumatic cognitions mediated the associations between infidelity-related PTSD symptoms and psychological health. This study included 73 adults (M age = 19.42, SE = 0.19 years) who experienced infidelity within a committed nonmarital relationship within the last 5 years. Controlling for gender, race, and exposure to Diagnostic and Statistical Manual of Psychiatric Disorders Criterion A traumas, 45.2% of our sample reported symptoms suggesting probable infidelity-related PTSD. Whether used as continuous or categorical predictor, infidelity-related PTSD symptoms were significantly associated with depressive symptoms, although results for perceived stress and anxiety symptoms were mixed.Post-traumatic cognitions acted as a partial mediator for depressive symptoms and full mediator for perceived stress and anxiety symptoms. This empirical evidence suggests that infidelity may produce PTSD symptoms at a relatively high rate, even in unmarried young adults, and may put individuals at risk for poorer psychological health, partially through post-traumatic cognitions.
K E Y W O R D Sclose relationships, infidelity, post-traumatic cognitions, post-traumatic stress, psychological health, PTSD, young adults