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Context In adults, cortisol levels show a pronounced 24-hour rhythm with a peak in the early morning. It is unknown at what age this early-morning peak in cortisol emerges during infancy, hampering the establishment of optimal dosing regimens for hydrocortisone replacement therapy in infants with an inborn form of adrenal insufficiency. Objective We aimed to characterize daily variation in salivary cortisol concentration across the first year of life. Methods We conducted a systematic review followed by an individual participant data meta-analysis of studies reporting on spontaneous (ie, not stress-induced) salivary cortisol concentrations in healthy infants aged 0-1 year. A one-stage approach using linear mixed-effects modeling was used to determine the interaction between age and time of day on cortisol concentrations. Results Through the systematic review, 54 eligible publications were identified, reporting on 29 177 cortisol observations. Individual participant data were obtained from 15 study cohorts, combining 17 079 cortisol measurements from 1904 infants. The morning/evening cortisol ratio increased significantly from 1.7 (95% CI: 1.3-2.1) at birth to 3.7 (95% CI: 3.0-4.5) at 6 to 9 months (P <.0001). Cosinor analysis using all available data revealed the gradual emergence of a 24-hour rhythm during infancy. Conclusion The early-morning peak in cortisol secretion gradually emerges from birth onwards to form a stable morning/evening ratio from age 6 to 9 months. This might have implications for hydrocortisone replacement therapy in infants with an inborn form of adrenal insufficiency. [ABSTRACT FROM AUTHOR]

The deleterious effects of marital conflict on youth outcomes are well-documented in both cross-sectional and longitudinal studies. To date, longitudinal studies have focused on repeated measures of youths' outcomes and the temporal dynamics of marital conflict have largely been ignored. Marital conflict changes over time as contextual and relationship characteristics change, and these patterns of change may provide unique predictive power in accounting for differences in youth outcomes. This study provides a novel exploration of an old idea by focusing on dynamic patterns of marital conflict in predicting trajectories of adolescents' adjustment. All variables were measured at ages 16, 17, and 18 with 252 adolescents (53% female) enrolled in the longitudinal Family Stress and Youth Development Study. Latent growth curve models with latent variable interactions were used to determine whether marital conflict at age 16 (intercept), change over time in marital conflict (slope), and the intercept--slope interaction predicted change over time in adolescent internalizing and externalizing symptoms and levels of internalizing and externalizing symptoms at age 18. Youth exposed to high and increasing levels of marital conflict reported high and stable levels of internalizing and externalizing symptoms across adolescence. Adolescents exposed to low and decreasing levels of marital conflict had consistently fewer symptoms. Furthermore, exposure to initially low but increasing levels of marital conflict was associated with increases in problems across adolescence, which contrasted with findings for youth with initially high marital conflict exposure that decreased over time. Findings are discussed in relation to both conceptual and methodological advances.

Many young children experience insufficient or poor quality sleep, which may have implications for adjustment and cognitive performance. This study tested group-level changes and rank-order stability in both daytime and nighttime sleep parameters over a six-month period, from fall to spring, among children receiving high-quality, center-based daycare. A total of 68 preschoolers (54% girls; M(subscript age) = 3.80 years, SD = 0.68) participated. Sleep was assessed via actigraphy for seven days and nights; sleep duration (actual sleep minutes) and quality parameters were derived. Analyses of group-level changes indicated that children's daytime and nighttime sleep duration did not change significantly from fall to spring. Nighttime sleep quality showed significant improvement, however, such that children had higher sleep efficiency in the spring than in the fall. Rank-order stability in both nighttime and daytime measures of sleep duration and quality was moderate, and stability in daytime sleep quality was low. Results add to a sparse literature examining stability in sleep parameters in young children using actigraphy.

The present study investigates how coordination between stress responsivity of the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS) moderates the prospective effects of marital conflict on internalizing and externalizing symptoms across adolescence. Although an important avenue for psychophysiological research concerns how PNS and SNS responses jointly influence adjustment in the context of stress, these processes have rarely been studied in adolescence or longitudinally. Participants were 252 youth (53% female, 66% European American, 34% African American) who participated in laboratory assessments when they were 16, 17, and 18 years old. PNS activity (measured via respiratory sinus arrhythmia [RSA]) and SNS activity (measured via skin conductance level [SCL]) were assessed during a resting baseline and in response to a laboratory-based challenge (star tracing). Parents and adolescents both reported on marital conflict and adolescents reported on their internalizing and externalizing symptoms. At higher levels of marital conflict, coactivation of PNS and SNS activity, characterized by increased RSA and increased SCL from baseline to challenge, predicted elevated internalizing symptoms and an increase in externalizing behavior across adolescence. Coinhibition, or decreased activity across both systems, also predicted an increase in internalizing symptoms over time. At lower levels of marital conflict, internalizing and externalizing symptoms were relatively low. Findings extend primarily cross-sectional work with younger children by demonstrating that coordination between the two branches of the autonomic nervous system (ANS) moderates the longitudinal effects of marital conflict on psychological and behavioral maladjustment among adolescents.

We examined children's sleep at age 9 as a predictor of developmental trajectories of cognitive performance from ages 9 to 11 years. The effects of sleep on cognition are not uniform and thus we tested race/ethnicity, socioeconomic status (SES), and sex as moderators of these associations. At the first assessment, 282 children aged 9.44 years (52% boys, 65% European American [EA], 35% African American [AA]) participated. Two more waves of data collection spaced 1 year apart followed. The majority of children (63%) were living at or below the poverty line. Children's sleep was measured objectively with actigraphy and 2 well-established sleep parameters were derived: duration, indexed by sleep minutes between sleep onset and wake time, and quality, indexed by efficiency. Multiple cognitive functioning domains were examined with the Woodcock Johnson Tests of Cognitive Abilities (WJ III). Across the sample, higher sleep efficiency, but not duration, was associated with better cognitive performance. Significant moderation effects emerged. Controlling for SES, AA children scored lower on general intellectual ability and working memory (WM) at age 11 only if they experienced lower sleep efficiency at age 9. Further, boys scored lower on general abilities and processing speed (PS) at age 11 only if their sleep efficiency was lower at age 9. Findings indicate that lower sleep efficiency may contribute to lower cognitive functioning especially for AA children and boys. These vulnerabilities appear to emerge early in development and are maintained over time. Results underscore the importance of individual differences in explicating relations between sleep and children's cognitive performance.

In past work, White Americans' beliefs about Black poverty have predicted lower perceived work ethic of the poor, and, thus, less welfare support. In this article, we examine whether beliefs about White poverty predict more positive attributions about the poor among three representative samples of White Americans. Study 1 reveals that White (but not Black) Americans' White-poor beliefs predict increased perceptions that welfare recipients are hardworking, which predict more welfare support. Study 2 demonstrates that the link between White Americans' White-poor beliefs and the humanization of welfare recipients is stronger among White Americans who feel intergroup status threat (i.e., those who hold racial zero-sum beliefs). Study 3 replicates and extends Study 2 by using an experimental approach. Together, these data suggest that White Americans' White-poor beliefs function to humanize welfare recipients as a means to justify policies that could help the ingroup, preserving the racial status quo. [ABSTRACT FROM AUTHOR]

Personality and sleep characteristics are related to financial attitudes and behaviors. However, to our knowledge no study has examined how personality and sleep may be conjointly associated with these financial outcomes. The present study examined sleepiness as a moderator of the associations between college students' personality traits and financial risk tolerance and spending habits. Undergraduates (N = 177, 77% women, 78% White) self-reported their personality traits and sleepiness using well-established questionnaires. Financial attitudes and behaviors were assessed via students' self-reported responses to a set of scenarios assessing risk tolerance as well as their spending habits over the prior two weeks. Multiple regression analyses were run. Across five significant two-way interactions, high levels of sleepiness exacerbated risk for greater financial risk tolerance and higher spending among those characterized by high open-mindedness and low neuroticism, whereas low sleepiness increased protection for lower risk tolerance and less spending among those high in agreeableness and conscientiousness. Sleepiness may act as both a vulnerability and protective factor in relations between personality and financial attitudes and behaviors. Improvements in sleepiness, which is modifiable via intervention, may have significant implications for individuals' financial well-being. [ABSTRACT FROM AUTHOR]

Prior work has demonstrated that greater community violence concerns are associated with poor sleep quality among adolescents. However, these effects may not be uniform across all youth. The present study examined the role of individual difference variables, physiological regulation and race, as moderators of risk in the relation between adolescents' community violence concerns and their sleep. Adolescents (N = 219; 55.3% female; 69.9% White/European American, 30.1% Black/African American) participated in the study when they were 18 years old (M = 17.7 years, SD = 1.0). Physiological regulation was assessed via respiratory sinus arrhythmia, a measure of parasympathetic regulation, at rest and in response to a stressor. Adolescents wore actigraphs for 7 nights to assess their sleep duration and quality, and reported on their community violence concerns via a well‐validated questionnaire. Results demonstrated a consistent pattern of interactions, such that African American adolescents who showed less adaptive patterns of regulating physiological arousal experienced shorter sleep duration and poorer sleep quality in the context of greater community violence concerns. Community violence concerns were not associated with sleep for White adolescents. The findings may suggest that race‐related stressors exacerbate risk for poor sleep among African American adolescents who experience more community violence concerns and have more difficulty regulating physiological arousal. Coping strategies for managing stress and arousal may be helpful for improving sleep for some youth. [ABSTRACT FROM AUTHOR]

Background & Objective: A growing body of work indicates that experiences of neighborhood disadvantage place children at risk for poor sleep. This study aimed to examine how both neighborhood economic deprivation (a measure of poverty) and social fragmentation (an index of instability) are associated with objective measures of the length and quality of children’s sleep. Participants: Participants were 210 children (54.3% boys) living predominantly in small towns and semirural communities in Alabama. On average children were 11.3 years old (SD =.63); 66.7% of the children were European American and 33.3% were African American. The sample was socioeconomically diverse with 67.9% of the participants living at or below the poverty line and 32.1% from lower-middle-class or middle-class families. Methods: Indicators of neighborhood characteristics were derived from the 2012 American Community Survey and composited to create two variables representing neighborhood economic deprivation and social fragmentation. Child sleep period, actual sleep minutes, and efficiency were examined using actigraphy. Results: Higher levels of neighborhood economic deprivation were associated with fewer sleep minutes and poorer sleep efficiency. More neighborhood social fragmentation was also linked with poorer sleep efficiency. Analyses controlled for demographic characteristics, child health, and family socioeconomic status. Conclusions: Findings indicate that living in economically and socially disadvantaged neighborhoods predicts risk for shorter and lower-quality sleep in children. Examination of community context in addition to family and individual characteristics may provide a more comprehensive understanding of the factors shaping child sleep. [ABSTRACT FROM AUTHOR]

Abstract: Influential biopsychosocial theories have proposed that some developmental periods in the lifespan are potential pivot points or opportunities for recalibration of stress response systems. To date, however, there have been few longitudinal studies of physiological stress responsivity and no studies comparing change in physiological stress responsivity across developmental periods. Our goals were to (a) address conceptual and methodological issues in studying the development of physiological stress responsivity within and between individuals, and (b) provide an exemplar for evaluating development of responsivity to stress in the parasympathetic nervous system, comparing respiratory sinus arrhythmia (RSA) responsivity from middle to late childhood with middle to late adolescence. We propose the use of latent growth modeling of stress responsivity that includes time‐varying covariates to account for conceptual and methodological issues in the measurement of physiological stress responsivity. Such models allow researchers to address key aspects of developmental sensitivity including within‐individual variability, mean level change over time, and between‐individual variability over time. In an empirical example, we found significant between‐individual variability over time in RSA responsivity to stress during middle to late childhood but not during middle to late adolescence, suggesting that childhood may be a period of greater developmental sensitivity at the between‐individual level. [ABSTRACT FROM AUTHOR]

Although the conceptual interplay among the biological and clinical features of sleep, arousal, and emotion regulation has been noted, little is understood about how indices of sleep duration and parasympathetic reactivity operate jointly to predict adjustment in early childhood. Using a sample of 123 toddlers, the present study examined sleep duration and RSA reactivity as predictors of internalizing and externalizing behaviors. Parents reported on children's sleep duration and adjustment. RSA reactivity was assessed via children's responses to fear-eliciting stimuli and an inhibitory control challenge. Findings demonstrated that greater RSA suppression to both types of tasks in combination with longer sleep duration was concurrently associated with less internalizing. In contrast, greater RSA augmentation to an inhibitory control task in the context of shorter sleep duration predicted more externalizing 1 year later. The significance of duration of toddlers' sleep as well as the context in which physiological regulatory difficulties occurs is discussed. [ABSTRACT FROM AUTHOR]