Stress, trauma, racial/ethnic group membership, and HPA function: Utility of hair cortisol.

Discrimination, poverty, and other aspects of the minority experience produce stress associated with health disparities. The hypothalamic-pituitary-adrenal (HPA) axis, a neuroendocrine subsystem usually monitored through assay of the hormone cortisol, is thought to play a key role in this relationship. Cortisol assay using hair specimens is a technology that promises to address important methodological problems in large-scale studies of health, well-being, and racial/ethnic status. The purpose of this study is to evaluate the potential of a hair cortisol assay-based method for studying trait-like HPA response to low to moderate levels of stress, associated with racial/ethnic discrimination and related social processes, among well-functioning young adults. The hair cortisol measure was shown to be highly reliable; it detected differences in gender and ethnic/racial identity and was correlated with a history of physical abuse and measures of experienced microaggression. The results support the promise of hair-based cortisol assay as a key methodology in health disparities research. Public Policy Relevance Statement This study examines the utility of hair cortisol assay as a method of examining racial/ethnic differences in trait-like stress. Discrimination, poverty, and other minority experiences play an important role in the experience of stress across the lifetime, and these are suspected of contributing to health disparities among minority groups. The present findings provide evidence that hair cortisol can have a valuable role in research on stress and health disparities in minority groups.