Sarah Enos Watamura

Morning-to-Afternoon Increases in Cortisol Concentrations for Infants and Toddlers at Child Care: Age Differences and Behavioral Correlates

This study examined salivary cortisol, a stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) axis hormone in 20 infants (12 females; M age = 10.8 months) and 35 toddlers (20 females; M age = 29.7 months) in full-day, center-based child care. Samples were taken at approximately 10:00 a.m. and 4:00 p.m. at child care and at home. At child care, 35% of infants and 71% of toddlers showed a rise in cortisol across the day; at home, 71% of infants and 64% of toddlers showed decreases. Toddlers who played more with peers exhibited lower cortisol. Controlling age, teacher-reported social fearfulness predicted higher afternoon cortisol and larger cortisol increases across the day at child care. This phenomenon may indicate context-specific activation of the HPA axis early in life.

Hypothalamic-Pituitary-Adrenal Axis Dysregulation in Dysphoric Children and Adolescents: Cortisol Reactivity to Psychosocial Stress from Preschool Through Middle Adolescence

BACKGROUND Most depressed adults exhibit dysregulation of the hypothalamic-pituitary-adrenal axis, including cortisol hyperreactivity to psychosocial challenge. In contrast, remarkably little is known about hypothalamic-pituitary-adrenal axis activity in response to psychosocial challenge among at-risk children and adolescents. This study examined cortisol response to psychosocial challenge in nondepressed, at-risk, dysphoric and nondysphoric control youth across different developmentally salient age groups (preschool, third-, sixth-, and ninth-graders). METHODS Two samples of youth (Study 1-preschoolers; Study 2-third-, sixth-, and ninth-graders) without a history of clinical depression were administered developmentally appropriate psychosocial challenges. Of these nondepressed children, we examined youth at high-risk (n = 60) and low-risk (n = 223) status, as defined by elevated but subthreshold dysphoric symptoms according to multiple informants. Cortisol levels were assessed before and after a psychosocial stressor. RESULTS Nondysphoric control youth at all ages displayed the expected cortisol rise to challenge followed by return to baseline. However, prepubertal, at-risk, dysphoric children--specifically preschoolers and third-graders--exhibited cortisol hyporeactivity to challenge, whereas postpubertal dysphoric adolescents (ninth-graders) displayed hyperreactivity to the stressor. Additional analyses revealed that this switch from cortisol hyporeactivity to hyperreactivity among at-risk, dysphoric youth occurred as a function of pubertal development. CONCLUSIONS Findings suggest a developmental switch in cortisol response for at-risk, dysphoric youth from preschool through adolescence and have implications for a developmental pathophysiological understanding of how at-risk youth across the lifespan might develop depressive disorder.

Hypocortisolism as a potential marker of allostatic load in children: associations with family risk and internalizing disorders.

Although the majority of research attention to the hypothalamic-pituitary-adrenal (HPA) axis in stress-related disorders and as a marker of allostatic load has focused on overactivation of this stress system, theory and data clearly indicate that underactivation is also an important type of dysregulation. In the current study we focused on low cortisol, exploring a constellation of risk factors including stress exposure, maternal depression, and attenuated basal and stress reactive cortisol in two samples of children. The first sample was comprised of 110 preschoolers living in high-stress environments. Cortisol was assessed across the day at home and at child care as well as across two stress paradigms. These data were used to classify whether childrens HPA axis activity was attenuated. Serious family financial strain, maternal depression, and attenuated cortisol all made unique contributions in models predicting current clinical levels of internalizing symptoms as rated by mothers and teachers. The second sample was 166 third, sixth, and ninth graders studied five times across a 1-year period. Maternal and child depression were determined through structured clinical interviews, and stress exposure was assessed via checklist and interview techniques with the child and parent. Cortisol was assessed multiple times across a lab visit at Time 1, and these data were combined into a single continuous measure. Cortisol concentrations across the lab visit interacted with stress exposure across the year such that children with lower average cortisol at Time 1 and increased stress across the 12 months showed elevated levels of internalizing symptoms. Based on these and related data we propose that prior to puberty low cortisol may be an important marker of allostatic load, particularly for risk of depression and anxiety.

Double jeopardy: poorer social-emotional outcomes for children in the NICHD SECCYD experiencing home and child-care environments that confer risk.

Using data from the National Institute of Child Health and Human Development Early Child Care Research Network (NICHD SECCYD), the authors examined whether interactions between home and child-care quality affect childrens social-emotional adjustment at 24, 36, and 54 months (N = 771). Triadic splits on quality of home and child care were used to examine children in specific ecological niches, with a focus on those who experience the double jeopardy of poor quality home and child-care environments. Children in this niche exhibited the highest levels of mother-reported problem behavior and the lowest levels of prosocial behavior. However, there was evidence that children from lower quality home environments were able to benefit from the compensatory influence of high-quality child care. These results suggest policies aimed at the cross-context influences of protective and risky settings.

Child care setting affects salivary cortisol and antibody secretion in young children

Elevated afternoon levels of cortisol have been found repeatedly in children during child care. However, it is unclear whether these elevations have any consequences. Because physiologic stress systems and the immune system are functionally linked, we examined the relationship between salivary cortisol concentration and antibody secretion across the day at home and in child care, and their relationships with parent-reported illnesses. Salivary antibody provides a critical line of defense against pathogens entering via the mouth, but little is known about its diurnal rhythm in young children or the effect of different environmental contexts. Saliva samples were taken at approximately 10:30 a.m., 3:30 p.m. and 8:00 p.m. on two child care and two home days in a sample of 65 3-5-year-old children attending very high quality, full time child care centers. Results indicated that (1) a rising cortisol profile at child care, driven by higher afternoon levels, predicted lower antibody levels on the subsequent weekend, (2) higher cortisol on weekend days was related to greater parent-reported illness, and (3) a declining daily pattern in sIgA was evident on weekend and child care days for older preschoolers, but only on weekend days for younger preschoolers. The results suggest that elevated cortisol in children during child care may be related to both lowered antibody levels and greater illness frequency.

The cortisol awakening response (CAR) in 2- to 4-year-old children: effects of acute nighttime sleep restriction, wake time, and daytime napping.

The cortisol awakening response (CAR) is presumed critically important for healthy adaptation. The current literature, however, is hampered by systematic measurement difficulties relative to awakening, especially with young children. While reports suggest the CAR is smaller in children than adults, well-controlled research in early childhood is scarce. We examined whether robust CARs exist in 2- to 4-year-old children and if sleep restriction, wake timing, and napping influence the CAR (n = 7). During a 25-day in-home protocol, researchers collected four salivary cortisol samples (0, 15, 30, 45 min post-wake) following five polysomnographic sleep recordings on nonconsecutive days after 4 hr (morning nap), 7 hr (afternoon nap), 10 hr (evening nap), 13 hr (baseline night), and 16 hr (sleep restriction night) of wakefulness (20 samples/child). The CAR was robust after nighttime sleep, diminished after sleep restriction, and smaller but distinct after morning and afternoon (not evening) naps. Cortisol remained elevated 45 min after morning and afternoon naps. .

Movement–attention coupling in infancy and attention problems in childhood

Adaptive behavior requires the integration of body movement and attention. Therefore, individual differences in integration of movement and attention during infancy may have significance for development. We contacted families whose 8‐year‐old children (n=26; 16 females, 10 males; mean age 8y 2mo, SD 8mo) participated in a previous study of movement‐attention coupling at 1 or 3 months of age, to assess parent‐reported attention or hyperactivity problems using the Child Behavior Checklist and Diagnostic and Statistical Manual of Mental Disorders (4th edn) criteria. Parent‐reported attention problems at 8 years of age were associated with less suppression of body movement at onset of looking, and greater rebound of body movement following its initial suppression at 3 months, but not at 1 month. Parent‐reported hyperactivity was not related to any of the infant movement–attention measures. Results suggests that the dynamic integration of movement and attention early in life may have functional significance for the development of attention problems in childhood.

The CIRCORT database: Reference ranges and seasonal changes in diurnal salivary cortisol derived from a meta-dataset comprised of 15 field studies

Diurnal salivary cortisol profiles are valuable indicators of adrenocortical functioning in epidemiological research and clinical practice. However, normative reference values derived from a large number of participants and across a wide age range are still missing. To fill this gap, data were compiled from 15 independently conducted field studies with a total of 104,623 salivary cortisol samples obtained from 18,698 unselected individuals (mean age: 48.3 years, age range: 0.5-98.5 years, 39% females). Besides providing a descriptive analysis of the complete dataset, we also performed mixed-effects growth curve modeling of diurnal salivary cortisol (i.e., 1-16h after awakening). Cortisol decreased significantly across the day and was influenced by both, age and sex. Intriguingly, we also found a pronounced impact of sampling season with elevated diurnal cortisol in spring and decreased levels in autumn. However, the majority of variance was accounted for by between-participant and between-study variance components. Based on these analyses, reference ranges (LC/MS-MS calibrated) for cortisol concentrations in saliva were derived for different times across the day, with more specific reference ranges generated for males and females in different age categories. This integrative summary provides important reference values on salivary cortisol to aid basic scientists and clinicians in interpreting deviations from the normal diurnal cycle.

Attentional dynamics of infant visual foraging

Young infants actively gather information about their world through visual foraging, but the dynamics of this important behavior is poorly understood, partly because developmental scientists have often equated its essential components, looking and attending. Here we describe a method for simultaneously tracking spatial attention to fixated and nonfixated locations during free looking in 12-week-old infants using steady-state visual evoked potentials (SSVEPs). Using this method, we found that the sequence of locations an infant inspects during free looking reflects a momentary bias away from locations that were recently the target of covert attention, quickly followed by the redirection of attention—in advance of gaze—to the next target of fixation. The result is a pattern of visual foraging that is likely to support efficient exploration of complex environments by facilitating the inspection of new locations in real time.

The effects of economic and sociocultural stressors on the well-being of children of Latino immigrants living in poverty.

Objective: This article explored whether preschoolers’ physical (body mass index [BMI] and salivary cortisol levels) and psychological (internalizing/externalizing behaviors) well-being were predicted by economic hardship, as has been previously documented, and further, whether parental immigration-related stress and/or acculturation level moderated this relationship in low-income Latino families. Method: The sample for the current study included 71 children of Latino immigrants (M = 4.46 years, SD = .62). Parents completed questionnaires assessing immigration-related stress, acculturation level, economic hardship, and child internalizing and externalizing behaviors. Child’s BMI was also calculated from height and weight. Salivary cortisol samples were collected midmorning and midafternoon at home on non-child-care days. Salivary cortisol values were averaged and log transformed. Results: Children’s salivary cortisol was predicted by an interaction between economic hardship and acculturation, with lower cortisol values except when children were protected by both lower acculturation and lower economic hardship. Both internalizing and externalizing behaviors were predicted by an interaction between economic hardship and immigration-related stress, with highest behaviors among children whose parents reported high levels of both economic hardship and immigration-related stress. Conclusions: The effects of economic hardship on the well-being of young children of Latino immigrants may depend on concurrent experiences of sociocultural stress, with detrimental effects emerging for these outcomes only when economic hardship and sociocultural stressors are high.