Children's objective and subjective sleep disruptions: links with afternoon cortisol levels.

OBJECTIVE: The purpose of this study was to determine possible relations between the quality and amount of children's sleep and cortisol in healthy children. DESIGN: Children's sleep was monitored with actigraphs for 7 nights. Children came to the laboratory to provide saliva samples, which were used to assess cortisol. Children reported on their sleepiness and sleep/wake problems. Sixty-four healthy children participated (M = 8.75 years; SD = .55). MAIN OUTCOME MEASURES: Self-reported sleepiness and sleep/wake problems, actigraphy-measured total sleep minutes, sleep efficiency, minutes awake after sleep onset, and sleep activity, and afternoon cortisol levels. Results: After controlling for demographic variables and child characteristics, higher levels of cortisol were related to increased subjective sleep problems and objective measures of shorter sleep duration and poorer sleep quality. CONCLUSION: These findings are of importance for understanding critical facets of children's health and well-being, and are noteworthy given the high prevalence of sleep disruptions in otherwise normally developing children in the United States.     

The father-daughter dance: the relationship between father-daughter relationship quality and daughters' stress response

The goal of the study was to determine whether father-daughter relationship quality is related to activity of the hypothalamic-pituitary-adrenal (HPA) axis (salivary cortisol) and autonomic nervous system (salivary alpha-amylase, sAA) in late adolescence-emerging adulthood during peer interactions. In the 1st study, reported father-daughter relationships characterized by rejection, chaos, and coercion had lower morning cortisol levels and were temperamentally more sensitive to emotional changes. In the 2nd study, young women who reported father-daughter relationships characterized by warmth, autonomy, support, and structure had lower pretask cortisol levels, and they had attenuated cortisol responses to problem discussion with a friend. In contrast, those who reported father-daughter relationships characterized by rejection, chaos, and coercion had higher pretask cortisol levels, had elevated cortisol in response to problem discussion with a friend, and were more likely to self-disclose about psychosocial stressors. No differences were observed between reported father-daughter relationship quality and sAA levels or task-related reactivity. The findings suggest that father-daughter interactions potentially influence both social cognition and HPA reactivity to developmentally salient stressors in young women.     

Father contributions to cortisol responses in infancy and toddlerhood

The current study is one of the first prospective examinations of longitudinal associations between observed father caregiving behaviors and child cortisol reactivity and regulation in response to emotional arousal. Observations of father and mother caregiving behaviors and child cortisol levels in response to challenges at 7 months and 24 months of child age were collected. Analyses were based on a subsample of children from the Family Life Project who lived with both their biological mothers and fathers and for whom there was at least partial cortisol data (7 months: n = 717; 24 months: n = 579). At the challenge conducted at 7 months of child age, 49.0% of the sample were girls; racial composition of the sample was 25.8% African American and 74.2% European American. At the challenge conducted at 24 months of child age 49.9% of the sample were girls; racial composition was 24.7% African American and 75.3% European American. We conducted analyses across assessment points simultaneously using mixed linear modeling for repeated measures data to test for differential effects of fathering across infancy and toddlerhood. Concurrent measures of father negativity were positively associated with greater increases in child cortisol levels in response to emotion challenge at 7 months (p = .01) and with higher overall levels of cortisol at 24 months (p < .001). However, there was no evidence that father caregiving during infancy independently predicted later cortisol activity during toddlerhood.     

Increased testosterone-to-cortisol ratio in psychopathy

Only a few studies have examined hormones in psychopathy, and results have been mixed. It has been suggested that because hormone systems are highly interconnected, it may be important to examine multiple systems simultaneously to gain a clearer picture of how hormones work together to predispose for a certain construct. In the present study, we attempt to clarify the role of the hormones cortisol and testosterone in psychopathy by examining both hormones in a community sample of 178 adults demonstrating a wide range of psychopathy scores. Results showed that psychopathy scores were associated with an increased ratio of testosterone (baseline) to cortisol responsivity to a stressor. Psychopathy was not associated with either of these measures independently or with baseline cortisol levels. These findings suggest that these highly interconnected hormone systems may work in concert to predispose to psychopathy.     

Peer Victimization and Aggression: Moderation by Individual Differences in Salivary Cortiol and Alpha-Amylase

This research examined whether variations in salivary measures of the hypothalamic-pituitary-adrenal axis (cortisol) and autonomic nervous system (alpha amylase [sAA]) contribute to individual differences in the association between peer victimization and aggression. Children (N = 132; M age = 9.46 years, SD = 0.33) completed a measure of peer victimization, teachers rated children’s aggression, and children’s saliva was collected prior to, and following, participation in a laboratory-based peer-oriented social challenge task. Children rated their level of frustration at the end of the task. Results revealed that victimization interacted with cortisol and sAA measured in anticipation of the task to predict aggression; the victimization × cortisol contribution to aggression was partly mediated by children’s self-reported frustration level. Victimization also was associated with heightened frustration in girls with high task-related sAA reactivity. Task-related sAA reactivity was associated with heightened aggression, but only for girls. These findings suggest that associations between peer victimization and aggression are moderated by variation in the activity of the major components of the psychobiology of stress; results are discussed in relation to theoretical models of individual differences in biological sensitivity to context.     

Equating tasks and sustaining attention in children and adults: The methodological and theoretical utility ofd’ matching

The present study develops a method to create task equivalency for children and adults in vigilance research. Experiment 1 employed the signal detection index of perceptual sensitivity (d’) to calibrate vigilance tasks for 32 children (ages 78) and 32 adults. The results of Experiment 1 suggest that task equivalency across groups can be attained, and a vigilance decrement was observed for children. In Experiment 2, the task parameter of event rate was manipulated across two vigils. Again, 32 children (ages 78) and 32 adults participated. The results suggest that a reverse event rate effect emerged for both children and adults. In addition, developmental differences in response to the event rate manipulation and with respect to the vigilance decrement emerged: Children benefited less from the manipulation and were more likely to demonstrate a vigilance decrement than were adults. No developmental differences emerged for the sensitivity decrement. The results are explained with reference to how task demands interact with participant arousal, and implications for development and for future research are discussed.