Cortisol Awakening Response Recalibration as a Function of Stress During Adolescence

• In Event: 3-069 - Multimodal Investigation of Childhood Adversity, Stress System Regulation, and Adolescent Physical and Mental Health

Integrative Statement

Introduction. The steep rise in cortisol occurring 30-45 minutes post-waking (cortisol awakening response, CAR) contributes to healthy restoration of physiological, cognitive, and motor functions following sleep (Clow, Hucklebridge, & Thorn, 2010). Across adolescence, CAR tends to increase with pubertal development (Oskis et al., 2009) and higher CAR has been associated with fewer psychopathology symptoms (Platje et al., 2013; Stetler & Miller, 2005). Childhood adversity predicts reduced CAR in adulthood (Gustaffson et al., 2010; Mangold et al., 2010); however, for children who experienced circumscribed adversity during infancy/toddlerhood, as is the case for post-institutionalized (PI) children, adolescence may represent a reopened sensitive period when physiological systems recalibrate to the current environment. One study found that PI children showed reduced CAR at earlier, but not later, pubertal stages (Quevedo et al., 2012). Another found that adversity not circumscribed to early childhood was associated with exaggerated CAR post-puberty (King et al., 2016). Thus, this study examined adolescent changes in CAR as a function of early and current life stress and associations with adolescent mental health.
Method. Participants were 7-15-year-olds (58% female, M age=11.2), including 130 post-institutionalized adolescents (PI) and 170 non-adopted adolescents (NA) raised in their biological families. Each year for two years, participants completed a semi-structured interview (Rudolf & Hammond, 1999) covering life stressors in peer and family domains over the past year. Each of 6 categories was rated on a 5-point Likert scale and averaged to create a continuous indicator of current life stress. [A more nuanced measure will be available by the time of SRCD that differentiates life stress and social support.] Participants also completed a three-day home saliva collection kit each year to assess the CAR (awakening to 30-minutes post-awakening) and caregivers completed the Macarthur Health and Behavior Questionnaire.
Results. A mixed-effects model with random intercepts was fitted for each group, controlling for sex and age, predicting log¬10-transformed cortisol. A dichotomous variable for sample (wake vs. 30-min) was included to model CAR slope. The interaction between year and year 1 life stress on wake-to-30-min slope was investigated to assess change in the CAR over time. This interaction was not significant for NA children (t=0.26, p=.79) but was for PI children (t=2.89, p=.004) such that at lower levels of year 1 stress, CAR became less steep over time (Figure 1). Similar results were obtained when controlling for pubertal stage instead of age. When a difference score was calculated to represent the cortisol increase from waking to 30-min, a smaller CAR and a smaller increase in CAR over the year was associated with an increase in parent-reported externalizing symptoms, regardless of group (t=-2.21, p=.03; t=-2.08, p=.04).
Discussion. These results add to an already-diverse body of literature exploring changes in CAR across adolescence following early life stress. It is yet unclear why low-stress PI children would show reduced CAR over time when this is associated with greater externalizing problems in the whole sample. However, results may become clearer when a more nuanced measure of stress and support, rather than global stress, is available.

Authors

• Carrie E DePasquale, Institute of Child Development
  Presenting Author

• Heather Taylor, University of Minnesota
  Non-Presenting Author

• Keira B. Leneman, University of Minnesota
  Non-Presenting Author

• Bonny Donzella, University of Minnesota
  Non-Presenting Author

• Megan Gunnar, University of Minnesota
  Non-Presenting Author