Inconsistencies exist in the current literature regarding hypothalamic-pituitary-adrenal (HPA) regulation following exposure to repeated stressful events. These inconsistencies stem, in part, from the limitations imposed by measuring cortisol in saliva or plasma (i.e. "point measures" of HPA activity). The present study used a cross-sectional, correlational design to examine the relationship between childhood stress (assessed using the adverse childhood experiences [ACEs] questionnaire) and hair cortisol (a biomarker of chronic HPA activity) in 55 healthy 18-24-year-old college students. Dichotomous ACE score for two models using different cut-points was significantly, inversely related to hair cortisol level (B = 1.03, p = 0.046 and B = 1.09, p = 0.031). These results are consistent with theoretical models where exposure to repeated stressful events results in chronic HPA dysregulation, which may include down-regulation under certain conditions.
Keywords: Stress; adverse childhood experiences; cortisol; health; hypothalamic–pituitary–adrenal axis.