The hypothalamic-pituitary-adrenal (HPA) axis is influenced by early life adversity; however, less is known about the potential for recovery following marked improvements in care. The present study examined longitudinal changes in children's cortisol reactivity in the laboratory (4 assessments over 2 years) after adoption. Post-institutionalized (N = 65) and post-foster care children (N = 49) demonstrated blunted reactivity relative to non-adopted peers (N = 53). Furthermore, post-institutionalized children exhibited no evidence of expected adaptation to repeated sessions in the 2 years following adoption. As evidenced by blunted cortisol reactivity, flatter diurnal slope, and lower home morning cortisol, we found support for hypocortisolism among children experiencing adverse early care. Hypocortisolism served as a mediator between adversity and teacher-reported attention and externalizing problems during kindergarten. Early adversity appears to contribute to the down-regulation of the HPA axis under both basal and stress conditions.
Bibliographical noteFunding Information:
The authors would like to thank the other members of the Minnesota International Adoption Project team for their efforts in collecting these data, including: Bao Moua, Kristin Frenn, and Meg Bale. We would also like to thank the parents and children without whom this study would not have been possible. This work was supported by grants R01 MH080905 and P50 MH078105 from the National Institute of Mental Health awarded to Megan Gunnar. Support was also provided to Kalsea Koss by National Institute of Mental Health training grants (T32 MH015755 and T32 MH018921) during the preparation of this article.
© 2015 Elsevier Ltd.
- Early adversity
- Hypothalamic-pituitary-adrenal axis
- Problem behavior