Neural correlates of parent-child HPA axis coregulation.

Parents and children have been found to show coordination or coregulation of the hypothalamic-pituitary-adrenal (HPA) axis. This coordination may be reflected in adolescents' neural activation to parent stimuli, particularly in regions of the brain associated with social information processing. This study reports on 22 adolescents (13 males, mean age 17years), recruited from a longitudinal study to participate in a functional MRI (fMRI) scanning protocol. Approximately 1.5years before the scan, these same adolescents participated in a family conflict discussion in the lab with both parents, and all three family members provided samples of salivary cortisol five times, before and after the discussion. Multilevel models found positive cross-sectional and time-lagged associations between parents' and youth cortisol. Empirical Bayes (EB) coefficients, extracted from these models to reflect the strength of the relationship between parent and adolescent cortisol, were tested in conjunction with adolescents' neural activation to video clips of their parents taken from the conflict discussion. For both mothers and fathers, youth who showed stronger cortisol coregulation with each parent (both in cross-sectional and time-lagged analyses) showed more activation to that same parent in posteromedial regions (precuneus, posterior cingulate, and retrosplenial cortex) that have been linked with social cognition, e.g. mentalizing about others' emotions. Youths' adrenocortical coregulation with their parents may be reflected in their neural processing of stimuli featuring those same parents.