This study examined the association between early life adversity, in the form of early rearing in an institution (orphanage), and the slope of cortisol in the first thirty minutes after waking in 277 children, aged 7 through 15 years old, who had either been adopted between 6 and 60 months of age into well-resourced homes in the United States or born into similar homes. The adopted youth were divided at the median (age 16 months) into those adopted earlier (earlier-adopted, EA) and later (later-adopted, LA). The purpose of this study was to examine the post-waking slope in cortisol in post-institutionalized youth, predicting that it would be blunted, especially in later-adopted youth, when compared to the non-adopted (NA) youth. A secondary goal was to examine whether there would be some evidence of less blunting of the first 30 min of the cortisol awakening response among the children further along in pubertal development (i.e., Pubertal Recalibration Hypothesis). Pubertal stage was determined by nurse exam. Salivary cortisol was assessed at 0 and 30-min post-awakening on three days. The results showed that LA children had a blunted wake-30 min cortisol slope relative to NA and EA children. Neither the age by group nor pubertal stage by group analyses were significant. However, the majority of the sample were in early stages of puberty (56% in stages 1 & 2), thus the power was low for detecting such an interaction. This is the first year of a cohort-sequential longitudinal study examining early experiences and pubertal influences on the HPA axis, so it will be important to re-examine this question as the sample ages.
Bibliographical noteFunding Information:
This study was funded by grant number R01 HD075349 (to MG) from the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) at the National Institute of Health (NIH). The authors wish to thank the many families and youth who participated in this study. We also thank the International Adoption Project. We thank Tori Simenec, Bao Moua, and Lea Neumann for their assistance with the study, as well as our nurses Janet Goodwalt, Terri Jones, and Melissa Stoll. Additionally, we thank Lorah Dorn for assistance in initial Tanner staging training. Finally, this study was conducted, in part, at the Center for Neurobehavioral Development at the University of Minnesota.
- Early life adversity
- Rise in cortisol