This study examines the relation between trauma, HPA-Axis dysregulation and PTSD symptoms as moderated by exposure to chronic life stress and parental stress. Sixty-three children and their parents participated in the study. Participants ranged in age from 7 to 14 years and were predominantly African-American. It was hypothesized (1) that there would be a significant positive relation between the number of traumatic events experienced and PTSD symptoms, and that this relationship would be moderated by both chronic stress and parental stress, such that as stress increased so would PTSD symptoms; and (2) that there would be a significant relation between exposure to trauma and HPA-Axis dysregulation, as measured by cortisol level, such that cortisol levels would show greater dysregulation under conditions of high trauma exposure than under conditions of low trauma exposure, and that this relationship would be moderated by both chronic stress and parental stress. Results revealed that children in the present sample endorsed high exposure to trauma and generally low cortisol levels, although trauma was not directly related to cortisol levels. Chronic stress moderated the relation between trauma and PTSD symptoms, such that as chronic stress increased, so did PTSD symptoms. Parental stress moderated the relation between trauma and PM cortisol, such that as parental stress increased, PM cortisol decreased. Additionally, chronic stress by parental stress moderated the relation between trauma and PTSD symptoms, as well as the relation between trauma and PM cortisol. Findings are interpreted within a psychobiological framework and suggest distinct biological processes for traumatic stress versus stress
