Nonhuman animal models reveal that the hypothalamic–pituitary–adrenocortical (HPA) axis calibrates to the harshness of the environment during a sensitive period in infancy. Humans exposed to depriving institutional care in infancy show reduced HPA axis responsivity, even years after they are placed in supportive, well-resourced families. This study examined whether puberty opens a window of opportunity to recalibrate the HPA axis toward more typical reactivity when children shift from harsh deprived conditions in infancy into supportive conditions in childhood and adolescence. Participants (n = 129 postinstitutionalized, 68.2% female; n = 170 comparison, 52.4% female) completed 3 annual sessions beginning at ages 7 to 15 (M = 11.28, SD = 2.31). Each session assessed pubertal stage via nurse examination and cortisol reactivity to the Trier social stress test for children. The linear mixed-effects model controlling for sex and between-individual differences in pubertal stage showed a significant group by pubertal stage interaction: within-individual increases in pubertal stage were associated with increases in cortisol stress reactivity for postinstitutionalized youth but not nonadopted comparison youth. This study indicates that pubertal development reopens a window of opportunity for the HPA axis to recalibrate based on significant improvements in the supportiveness of the environment relative to that in infancy. The peripubertal period may be an important time in development where the caregiving environment has a substantial impact on the HPA axis and, perhaps, other stress-mediating systems. Future research is needed to examine the mechanisms of recalibration and whether HPA recalibration impacts physical and psychological health.
|Number of pages
|Proceedings of the National Academy of Sciences of the United States of America
|Published - Nov 26 2019
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS. This study was funded by National Institute of Child Health and Human Development Grant R01 HD075349 (to M.R.G.), National Institute of Mental Health Grant T32 MH015755 (to C.E.D.), and NSF Graduate Research Fellowship 00039202 (to B.M.R.). The content is solely the responsibility of the authors and does not represent the views of the National Institutes of Health or the National Science Foundation. The authors wish to thank the families who participated, the International Adoption Project, and the Center for Neurobehavioral Development at the University of Minnesota. We also thank Tori Simenec, Bao Moua, Lea Neumann, Heather Taylor, and Dr. Chris Desjardins for their assistance with the study; our nurses Janet Goodwalt, Terri Jones, and Melissa Stoll for Tanner staging; and Drs. Brad Miller and Lorah Dorn for providing training in pubertal assessment.
- Early life stress
- HPA axis
- Nstitutional care