The Association Between Parent and Child Self-Reported Stress and Child Hair Cortisol in Internationally-Adopted and Comparison Youth

Abstract

Biological embedding occurs when children’s physiology is shaped by caregiving context, but how such embedding occurs is still being explored. The hypothalamic-adrenal-axis (HPA) and its end product, cortisol, is a target for biological embedding. Here, we explore whether parents’ stressful experiences are reflected in their child’s HPA function, and whether this is dependent on shared genetics and/or shared experience. As part of an ongoing study, 67 youth (54% female, M age=14.9 years) and a parent completed the Stress and Adversity Inventory (STRAIN), which indexed physical and mental health symptoms, count of stressful events, and severity of stressful events for parent and child. Youth provided a 3 cm hair sample for cortisol determination (HCC). 32 youth (21 female) were adopted from institutional care before age 5. Parent STRAIN is unrelated to child: sex, group, or age; Parent and Child STRAIN are uncorrelated. Child STRAIN is related to age, sex, group such that older, female, and adopted youth show higher STRAIN; it does not predict Child HCC. Parent STRAIN is reflected in Child HCC: a regression predicting HCC from adoption status, parent STRAIN, and their interaction is significant, R²=.13, p=<.05, with parent STRAIN contributing significantly, β=.42, t=2.66, p<.05. Youth living with parents under greater strain demonstrate greater HCC. These early findings demonstrate evidence of biological embedding of parent strain into child HPA functioning. The study is ongoing and longitudinal: a larger sample will provide power to detect patterns and change over time.