Morning-to-afternoon increases in cortisol concentrations for infants and toddlers at child care: age differences and behavioral correlates

The impact of daily affective touch on cortisol levels in institutionalized & fostered children

Institutionalized children are often deprived of affective touch. Such tactile deprivation often leads to constant stress, as measured by the levels of salivary cortisol. We report here the impact of an affective touch program, optimized to activate a specific population of unmyelinated mechanosensitive nerves in the skin called c-tactile afferents (CT) on stress resistance. Two populations of children (age 4-10) were recruited: (i) a cohort living in an orphanage and (ii) a fostered cohort. Both groups received the affective touch program daily for 10-15 min for 5-6 weeks. A cohort of age-matched children living in a family environment acted as a control group and did not receive any instructions for tactile stimulation. Salivary cortisol was collected at the beginning (T1) and at the end (T2) of the study in all three groups. For institutionalized and fostered children there was a significant improvement in the level of cortisol (p < 0.0001) between T1 and T2, which is manifested in the balancing cortisol levels: a decrease where it was elevated and an increase, where the critically low level testified to the distress of the child. Balancing cortisol levels is a process of recovery to normal values, which indicates the restoration of neurohumoral mechanisms of stress regulation. The effect of balancing cortisol levels was more pronounced in the group of fostered children compared to the group of orphanage children (p = 0.0326). The children in the control group had no significant differences.

Latent profile analysis of diurnal cortisol patterns at the ages of 2, 3.5, and 5 years: Associations with childcare setting, child individual characteristics, and maternal distress

This study performed latent profile analysis from more than 4000 saliva cortisol samples collected from children at the ages of 2 (T1), 3.5 (T2), and 5 years (T3). Three clearly different cortisol profiles were identified. The largest group at every age point was the Low/Regular latent profile, in which the cortisol slopes followed typical diurnal variation. A smaller proportion of the children belonged to the latent profile with relatively Low/Flat slope, and a minority belonged to the High/Fluctuating latent group, where the overall cortisol values and variations between the slopes were clearly higher than in the other groups. Most of the children who belonged to the High/Fluctuating group were cared for at home, they had higher temperamental surgency and their mothers had more depressive symptoms than in the other latent profile groups. However, only moderate intraindividual stability in diurnal cortisol profiles was observed across the follow-up period. On average, half of the children moved between the groups from T1 to T3. Neither child temperament, social competence, nor sex explained the stability or movement between the groups across age. Variations in cortisol profiles may be caused by the child's age, and diurnal cortisol rhythm becomes more regular along with development. Methodological issues regarding saliva cortisol research in young children are discussed. Also, more longitudinal research is needed to clarify mechanisms between environmental as well as individual factors and possible dysregulation in a child's HPA axis functioning.

Prioritizing Connectedness and Equity in Speech-Language Services for American Indian and Alaska Native Children

PURPOSE

American Indian and Alaska Native (AI/AN; Indigenous) students are at a high risk for language and learning disorders. This article aims to highlight how clinicians can use decolonization and Indigenization pedagogies when planning and delivering speech-language services to Indigenous students from the perspectives of Indigenous professionals. These efforts can help promote student resilience, well-being, and identity and are critical to addressing educational inequity and provide culturally responsive services to Indigenous children. Many AI/AN students receive IDEA Part B special education services including speech and language therapy. Many of these students are misidentified as needing special education due to unique learning and language environments (Soto-Boykin et al., 2021). These students bring a unique cultural heritage that is vital to their identity, well-being, health, and school success. Therefore, the goal should be to provide evidence-based services that are culturally tailored and meet the whole child. Using a precision public health approach to consider social determinants of health and historical trauma allows for leveraging of a multilayered, trauma-informed approach to addressing educational inequities.

CONCLUSIONS

An Indigenous connectedness framework can be used to indicate how connectedness is essential to AI/AN child well-being. This framework can be interlaced with existing learning theories to shape instruction where indigenization is a cornerstone of learning. Further examined was the influence of historical trauma, racism, socioeconomic status, and culture loss on learning and language development in AI/AN children in the context of settler colonialism. Strategies on how to use Indigenous knowledge and evidence-based teaching practices were applied to therapeutic services offered by speech-language pathologists and educators.

The impact of time of entrance to center-based care on children’s general, language, and behavioral development

There are contrasting results of the association between center-based care attendance and child development, mainly related to how the time of entry and permanence in the program relates to developmental outcomes. Using latent class analysis in a nationally representative sample of Chilean children between 6 and 35 months old ( n = 3,992), and controlling for the child’s age, maternal education, mother’s marital status, and household income, we identify three different timings of entrance in center-based care programs. The three timings of entrance were defined as early-entry (16%), those children who are more likely to enter before they are 6 months old; middle-entry (16%), those who are more likely to enter when they are between 6 and 18 months old; and late-entry (68%), those children with a low probability of enrollment any time before they are 35 months old. We found that children from the early- and middle-entry classes had higher language development when compared with children from the late-entry class. Still, only those from the middle-entry class showed higher general development in the Battelle test. In contrast, children in the early- and middle-entry classes presented higher scores in the Child Behavior Checklist’s externalizing behavior scale than children in the late-entry class. Our findings highlight the existence of a likely linkage between the timing of entry to center-based care and child development. It is essential to understand the potential advantages of center-based care in younger children, especially in enhancing their vocabulary and general development, and the potential negative association of early-entry with problematic behavior.

Prosocial Behavior in Preschoolers: Effects of Early Socialization Experiences With Peers

Over the last decades, many studies had focused on the psychological outcomes of children who have received early socialization outside of the family context, highlighting that the daycare experience can both positively and negatively influence the child’s social-emotional development. Despite the number of studies conducted, there is a lack of observational research on this topic. The purpose of this study is to investigate whether the early daycare experience can influence the prosocial behaviors that children exhibit during free-play social interactions with peers, focusing on their quantity and quality. In addition, the associations between the enactment of prosocial behaviors and social-emotional and behavioral competence were investigated. 160 preschoolers, 77 of whom had previously attended daycare, participated in the study and were focally observed during two free play sessions with peers. Each prosocial behavior was identified and subsequently classified using a coding scheme designed to consider the self-initiated or required origin of prosocial actions and their underlying motive. Emotion comprehension was measured using a standardized test, while social-emotional and behavioral competence was assessed using a questionnaire filled out by teachers. The main findings showed that children who had attended daycare had higher anger and aggression scores than those who had not, who, in turn, were rated by their teachers as having more internalizing behaviors. These characteristics seemed to account for the differences found in the tendency to act prosocial acts in response to a peer’s request, which was lower in children who had a previous daycare experience. Moreover, early socialization outside of the family context appeared to foster the comprehension of others’ intent to achieve emotional or instrumental personal goals and, at the same time, to reduce conventional/affiliative prosocial acts. Overall, this study suggested that the incidental effects of daycare on prosocial behavior might be canceled due to the peculiar social-emotional and behavioral characteristics of the two groups of children.

Change in toddlers' cortisol activity during a year in childcare. Associations with childcare quality, child temperament, well-being and maternal education

Elevated levels of the stress hormone cortisol have been found in toddlers in childcare. Measuring cortisol may provide an indication of children's experiences in childcare and help to adjust practices better to their needs. To the best of our knowledge, toddlers' cortisol levels in childcare have not yet been investigated longitudinally. Furthermore, it is unclear which child and childcare factors contribute to cortisol elevation in toddlers. Using linear mixed model analyses, we investigated the full-day cortisol activity (10.00 h, 15.00 h, 18.00 h) of 156 toddlers (81 female, 56 male) during a year in childcare (September, January, June). We also investigated child cortisol levels at home in January. In addition, we tested the relation between cortisol activity and changes in cortisol activity across the year and childcare quality, temperament, well-being in childcare, and maternal education. We found increasing evening cortisol levels through the year while controlling for age. Afternoon cortisol levels were stable, but above morning cortisol levels in September and January and only slightly below morning cortisol levels in June. At home in January, afternoon levels were significantly below morning levels. Higher well-being in childcare was associated with lower overall cortisol levels and less increase in evening cortisol levels through the year in childcare. Further, less active toddlers seemed to accumulate some stress during the childcare day, indicated by higher evening cortisol levels. Rising evening cortisol levels may indicate accumulating stress across the year. Results point toward childcare being demanding for toddlers and their need for consideration from caregivers and parents, also after a longer period of childcare attendance. The findings underline the importance of observing, promoting, and further researching children's well-being in childcare.

Do responsive sleep interventions impact mental health in mother/infant dyads compared to extinction interventions? A pilot study

Methods to improve sleep in infants commonly involve some ignoring (extinction) but are often unpopular with mothers worried about infant distress when left to cry. Alternative more responsive methods are needed. This pilot study evaluated stress, maternal depressive symptomology and sleep in mother/infant dyads, between Responsive, Controlled Crying and Control groups. From 199 mother/infant dyads from any cultural background, 41 infants 4-12 months were randomly allocated to Responsive (RG, n = 15), Controlled Crying (CCG, n = 18) or Controls (Treatment as Usual, TAUG, n = 8), with 10 withdrawing after randomisation. Infant sleep (7-day sleep diaries) and stress (oral cortisol on two nights), maternal self-reported stress (Subjective Units of Distress, SUDS), maternal perceived infant distress (MPI-S) and symptoms of maternal depression (Edinburgh Post-natal Depression Scale, EPDS) were measured four times across 8 weeks. Sleep duration was not different between groups but Responsive woke less (p = .008). There were no differences in cortisol between groups across time points. Maternal SUDS was positively correlated with infant cortisol and MPI-S (p < 0.05) and mothers in the Responsive group were significantly less stressed (p = 0.02) and reported less symptoms of depression (p < 0.05). Findings in this small sample show Responsive methods are comparable to the extinction (Controlled Crying) in sleep outcomes but from a relational and maternal mental health perspective, are less stressful, offering families potential choices of sleep interventions.

Psychophysiological adjustment to formal education varies as a function of peer status and socioeconomic status in children beginning kindergarten

The transition to kindergarten can be stressful as children adjust to novel separations from their caregivers and become accustomed to their peer group. A 9-month study of 96 children (M_age  = 5.37 years, SD = 0.42) from Barranquilla, Colombia, assessed socioeconomic differences in hypothalamic-pituitary-adrenal (HPA) axis functioning across the kindergarten year. Children were from four different classrooms in one school. Saliva samples were collected twice a day across 3 consecutive days at the beginning and end of the school year. We examined whether change in HPA axis activation across the year varied as a function of a child's socioeconomic status (SES) and experience in the peer group. We found that rejected children and lower SES children had lower cortisol levels early in the morning. Rejected children had a flatter morning cortisol slope. Lower SES children had higher cortisol than their higher SES peers at the end of the school year and a flatter morning cortisol slope. Taken together, these findings suggest that diurnal cortisol in children beginning kindergarten may be influenced by both peer rejection and SES.

Children's diurnal cortisol output and temperament in two different childcare settings at 2 and 3.5 years of age

Prior research suggests that child temperament may play an important role in early childhood stress regulation. We compared children's diurnal cortisol and the association between cortisol and temperament in two different childcare settings. Cortisol was measured from saliva samples over 2 days in children (N = 84) attending out-of-home childcare and in children (N = 27), who were cared for at home at the age of 3.5 years. There was no difference between the childcare groups in total diurnal cortisol. However, of the individual measurements, afternoon cortisol levels were higher in the out-of-home childcare group during their childcare day when compared with their home day. Child temperament was not associated with total diurnal cortisol. Comparison with our prior measurements showed that the association between temperamental surgency/extroversion and total diurnal cortisol diminished along with the child age from 2 to 3.5 years in both childcare settings. This may indicate that more extroverted children are physiologically more reactive to environmental stimuli when they are younger, but this association does not appear as the children develop. Our results further suggest that the afternoon hours in the out-of-home childcare may be demanding and accelerate the hypothalamus-pituitary-adrenal axis activation in young children independent of their age.

Children's hair cortisol as a biomarker of stress at school: a follow-up study

In a previous study, we examined hair cortisol concentrations (HCCs) in children when first entering elementary school (at 4 years). In this follow-up study, we examined their HCC when they entered third grade (at 6 years), where the more playful first grades proceed into a more formal learning setting. Participants were 30 6-year-old children (14 boys). Hair samples (≥5 cm) were collected 2 months after the summer holidays. Hair analysis was conducted using two 2-cm long segments, reflecting the first 2 months of school attendance in grade 3 (the scalp-near segment), and 2 months prior to the start in grade 3. Between these two sections, we left a gap of 1 cm to avoid overlap of periods (due to differences in hair growth rate). Children showed a significant increase in cortisol levels when they entered third grade. This increase was not associated with social fearfulness or academic achievement, but did show significant associations with inhibitory control: children with less inhibitory control had higher cortisol levels after entering third grade, and larger increases in cortisol than children with higher scores on inhibitory control. This suggests that the ability to inhibit or control impulsive responsivity is important for children's stress regulation when making the transition to a more formal school environment.

Toddlers' diurnal cortisol levels affected by out-of-home, center-based childcare and at-home, guardian-supervised childcare: comparison between different caregiving contexts

Previous research suggests that attending non-parental out-of-home childcare is associated with elevated cortisol levels for some children. We aimed to compare diurnal saliva cortisol levels between children having out-of-home, center-based childcare or those having at-home, guardian-supervised childcare in Finland. A total of 213 children, aged 2.1 years (SD = 0.6), were drawn from the ongoing Finnish birth cohort study. Saliva samples were collected over 2 consecutive days (Sunday and Monday), with four samples drawn during each day: 30 min after waking up in the morning, at 10 am, between 2 and 3 pm, and in the evening before sleep. These results suggest that the shapes of the diurnal cortisol profiles were similar in both childcare groups following a typical circadian rhythm. However, the overall cortisol levels were on average 30% higher (95% CI: [9%, 54%], p = .004) with the at-home childcare in comparison with the out-of-home childcare group. Furthermore, a slight increase in the diurnal cortisol pattern was noticed in both groups and in both measurement days during the afternoon. This increase was 27% higher ([2%, 57%], p = .031) in the out-of-home childcare group during the out-of-home childcare day in comparison with the at-home childcare day. The elevated afternoon cortisol levels were partly explained by the afternoon naps, but there were probably other factors as well producing the cortisol rise during the afternoon hours. Further research is needed to define how a child's individual characteristic as well as their environmental factors associate with cortisol secretion patterns in different caregiving contexts.

Child Temperament and Total Diurnal Cortisol in Out-of-Home Center-Based Child Care and in At-Home Parental Care

The association between child temperament characteristics and total diurnal saliva cortisol in 84 children (M = 2.3 years, SD = 0.6) attending out‐of‐home, center‐based child care and 79 children (M = 2.0 years, SD = 0.5) attending at‐home parental care was examined. Saliva samples were collected during two consecutive days, that is, Sunday and Monday, with four samples taken per day. While children higher in surgency had higher total diurnal cortisol production, we did not find evidence that temperament moderated the associations between child‐care context and total diurnal cortisol. Negative affectivity and effortful control were not related to cortisol output. Our findings suggest that temperamental surgency may be associated with higher total cortisol production in early childhood across child‐care settings.

Poverty, Caregiving, and HPA-Axis Activity in Early Childhood

The association between poverty and the activity of the hypothalamic pituitary adrenal (HPA) axis in early childhood is well established. Both ecological and transactional theories suggest that one way in which poverty may influence children's HPA-axis activity is through its effects on parents' behaviors, and over the past three decades a substantial literature has accumulated indicating that variations in these behaviors are associated with individual differences in young children's HPA-axis activity. More recent research suggests that non-parental caregiving behaviors are associated with HPA-axis activity in early childhood as well. Here we systematically review the literature on the association between both parental and non-parental caregiving behaviors in the context of poverty and the activity of the HPA-axis in early childhood. We conclude by noting commonalities across these two literatures and their implications for future research.

The relationships among MAOA, COMT Val158Met, and 5-HTTLPR polymorphisms, newborn stress reactivity, and infant temperament

INTRODUCTION

Variance in hypothalamic-pituitary-adrenal (HPA) axis reactivity is considered to be one of the sources of differences in infant temperament. The cortisol enters into interactions with dopamine and serotonin, so it is expected that polymorphisms in genes coding monoamine metabolism influence both HPA axis reactivity and temperament.

METHODS

We therefore explore the relationship among 5-HTTLPR S/L, MAOA H/L, and COMT Val158Met polymorphisms, the stress reaction of newborn infants after a heel stick blood draw (measured by determining salivary cortisol at three time points), and temperament assessed at the age of 3 months using Rothbart's Infant Behavior Questionnaire-Revised (IBQ-R) with a sample of 84 infants.

RESULTS

The decrease in the salivary cortisol correlated with nine primary scales and all three secondary scales of IBQ-R. Children with a greater cortisol decrease were assessed as less susceptible to negative emotions, more extraverted, and more regulated. The polymorphisms that were observed were related both to the course of the stress reaction and to temperament. The 5-HTTLPR S allele was connected to higher scores for Negative Emotionality and lower scores for Orienting/Regulatory Capacity. The presence of the MAOA L allele predisposed its carriers to higher scores for Negative Emotionality, lower scores for Orienting/Regulatory Capacity, and a lower decrease in cortisol. The Met allele of COMT Val158Met polymorphism was connected to a higher Positive Affectivity/Surgency and Orienting/Regulatory Capacity and a greater cortisol decrease.

CONCLUSIONS

Contrary to previous studies referring mainly basal cortisol and its increase, the results of our study emphasize the importance of cortisol elimination in infant temperament. Another interesting finding was a higher cortisol increase, higher Distress to Limitations, Negative Emotionality, and Approach in MAOA LL homozygotes which are traditionally understood as more vulnerable toward early stress in developing later externalizing behavior.

The contribution of childhood adversity to cortisol measures of early life stress amongst infants in rural India: Findings from the early life stress sub-study of the SPRING cluster randomised controlled trial (SPRING-ELS)

BACKGROUND

The majority of the world's children live in low- and middle-income countries and face multiple obstacles to optimal wellbeing. The mechanisms by which adversities - social, cultural, psychological, environmental, economic - get 'under the skin' in the early days of life and become biologically embedded remain an important line of enquiry. We therefore examined the contribution of childhood adversity through pregnancy and the first year of life to hair and salivary cortisol measures of early life stress in the India SPRING home visits cluster RCT which aims to improve early childhood development.

METHODS

We assessed 22 adversities across four domains: socioeconomic, maternal stress, family-child relationship, and child and summed them to make a cumulative adversity score & quintiles, and four subscale scores. We cut 3 cm of hair from the posterior vertex and took three saliva samples from morning till late afternoon on each of two days (total six samples). We analysed both for cortisol concentration using ELISA techniques. We used multiple linear regression techniques to assess the relationship between cumulative adversity and log hair cortisol concentration and saliva diurnal slope and area under the curve.

RESULTS

We assessed 712 children for hair, and 752 children for saliva cortisol at 12 months of age. We found a strong positive relationship between adversity and hair cortisol; each additional adversity factor was associated with hair cortisol increases of 6.1% (95% CI 2.8, 9.4, p < 0.001) and the increase from adversity quintile one to five was 59.4%. Socioeconomic, relationship and child scales were independent predictors of hair cortisol (socioeconomic 6.4% (95% CI -0.4, 13.6); relationship 11.8% (95% CI 1.4, 23.2); child 7.9% (95% CI -0.5, 16.9). We did not find any association between any measures of adversity and either of the saliva cortisol outcomes.

DISCUSSION

This is the largest study of hair cortisol in young children, and the first in a low- and middle-income country setting. Whilst the short-term diurnal measures of cortisol did not appear to be linked with adversity, chronic exposure over several months appears to be strongly associated with cumulative adversity. These findings should spur further work to understand the specific ways in which adversity becomes biologically embedded, and how this can be tackled. They also lend support to ongoing action to tackle childhood adversity in communities around the world.

Maternal experiences of trauma and hair cortisol in early childhood in a prospective cohort

BACKGROUND AND OBJECTIVE

Maternal trauma can have intergenerational consequences but little is known about whether maternal traumas affect key biological domains associated with mental health in their offspring. The objective of this study was to examine maternal lifetime history of traumatic events through mid-gestation in relation to offspring cortisol production in early childhood.

METHODS

The sample was comprised of 660 children (49.9% Black, 44.4% White) from a longitudinal study of mother-offspring dyads in Shelby County, Tennessee, followed from mid-gestation to child age 4 years (enrolled 2006-2011). Maternal lifetime history of traumatic life events were assessed mid-gestation using the Traumatic Life Events Questionnaire. Total cortisol output among offspring was measured using hair cortisol concentrations at ages 1 to 4 years.

RESULTS

Associations of maternal trauma history with child hair cortisol varied by child's age. No association was observed at age 1 or 2. In adjusted regression models, at ages 3 and 4, offspring of mothers in the third (β = 0.99, P < .01), fourth (β=0.72, P < .05), and fifth (β=0.83, P < .01) quintiles of trauma exposure history had elevated (natural log) hair cortisol concentrations, relative to mothers in the lowest quintile (P-trend = 0.003). The associations were not attenuated after adjustment for theorized pathways, including premature birth, maternal postpartum depression, and maternal parenting stress.

CONCLUSIONS

Maternal lifetime trauma exposures are associated with offspring hair cortisol concentrations. Future research is needed to determine intermediary mechanisms and functional significance of elevated hair cortisol concentration in young children.

Ameliorating the biological impacts of childhood adversity: A review of intervention programs

Childhood adversity negatively impacts the biological development of children and has been linked to poor health outcomes across the life course. The purpose of this literature review is to explore and evaluate the effectiveness of interventions that have addressed an array of biological markers and physical health outcomes in children and adolescents affected by adversity. PubMed, CINAHL, PsychInfo, Sociological Abstracts databases and additional sources (Cochrane, WHO, NIH trial registries) were searched for English language studies published between January 2007 and September 2017. Articles with a childhood adversity exposure, biological health outcome, and evaluation of intervention using a randomized controlled trial study design were selected. The resulting 40 intervention studies addressed cortisol outcomes (n = 20) and a range of neurological, epigenetic, immune, and other outcomes (n = 22). Across institutional, foster care, and community settings, intervention programs demonstrated success overall for improving or normalizing morning and diurnal cortisol levels, and ameliorating the impacts of adversity on brain development, epigenetic regulation, and additional outcomes in children. Factors such as earlier timing of intervention, high quality and nurturant parenting traits, and greater intervention engagement played a role in intervention success. This study underlines progress and promise in addressing the health impacts of adversity in children. Ongoing research efforts should collect baseline data, improve retention, replicate studies in additional samples and settings, and evaluate additional variables, resilience factors, mediators, and long-term implications of results. Clinicians should integrate lessons from the intervention sciences for preventing and treating the health effects of adversity in children and adolescents.

The Games Infants Play: Social Games During Early Mother-Infant Interactions and Their Relationship With Oxytocin

The present study examined early social game routines during natural face-to-face mother–infant interactions and their relationship with oxytocin. Forty-three mother–infant dyads were observed, when infants were 4 months old, during a procedure involving a baseline and a natural interaction, where mothers were instructed to interact with their infants as they would at home. During this procedure four saliva samples from mothers and infants were collected to determine levels of oxytocin at different time points. Social game routines and infant social engagement (gaze, positive, and negative affect) were coded during the natural interaction. Social games were observed in 76.7% of the mother–infant dyads, and 46 different types of games were identified. Mothers initiated games to re-engage infants significantly more often than when infants were already engaged with them. During the games, infants showed more positive affect and less negative affect in comparison to the rest of the interaction. Finally, maternal increase in oxytocin from before to after the natural interaction was positively correlated with game rate and time spent in games, while infant increase in oxytocin from before to after the natural interaction was inversely related to game rate. These results indicate that social games are an inherent part of early mother–infant interactions, and their occurrence is associated with oxytocin of both infants and mothers.

Mandatory Naptimes in Childcare do not Reduce Children's Cortisol Levels

The majority of preschool children (aged 3–5 years) no longer habitually nap, yet in childcare settings daily mandated naptimes in which children lie down without alternative activity remains a common practice. Mandated naptimes are associated with observed reductions in emotional climate and increased incidence of distress. While intended to be restful, mandatory naptimes may induce stress in those children unable to sleep. To examine this possibility, we applied a 2 (mandated/flexible practice) × 2 (nap/no-nap) design to test group difference in stress responses of children (N = 43, mean age 56.3 months). Salivary cortisol level was measured at 4 time-points (waking, pre-naptime, post-naptime, and bedtime) across two days at childcare. Overall our results show a significant decline in cortisol level from wake to pre-naptime and from post-naptime to bedtime. No significant change in cortisol level was observed from pre- to post- naptime. Significant group differences in cortisol patterns were observed. Notably, children under mandatory naptime conditions who did not nap showed no significant reduction in cortisol level from post-naptime to bedtime. While cortisol measurement suggests naptime is neither stressful nor restful for children in any group, implications for bedtime arousal are raised for those unable to sleep under conditions of mandated naptimes.

A state-trait model of cortisol in early childhood: Contextual and parental predictors of stable and time-varying effects

This study examined state-trait models of diurnal cortisol (morning level and diurnal slope), and whether income, cumulative risk and parenting behaviors predicted variance in trait and state levels of cortisol. The sample of 306 mothers and their preschool children included 29% families at or near poverty, 27% families below the median income, and the remaining families at middle and upper income. Diurnal cortisol, income, cumulative risk, and parenting were measured at 4 time points, once every 9months, starting when children were 36-40months. State-trait models fit the data, suggesting significant state but not trait variance in cortisol. Low income and cumulative risk were related to trait levels of diurnal cortisol with little evidence of time-varying or state effects. Stable levels of parenting predicted trait levels of diurnal cortisol and time-varying levels of parenting predicted time-varying state levels of diurnal cortisol. Findings highlight the allostatic process of adaptation to risk as well as time-specific reactivity to variability in experience.

Investing in the Early Childhood Mental Health Workforce Development: Enhancing Professionals' Competencies to Support Emotion and Behavior Regulation in Young Children

This paper delineates a preventive approach to early childhood mental health by preparing the workforce to provide relational, sensitive care to young children ages 0-5. One of the most prevalent issues in early childhood is behavioral challenges and the inability of young children to regulate themselves. This leads to an expulsion rate in early childhood (3-4 times higher than K-12 expulsion rate) and future mental health issues. The Early Childhood Social-Emotional and Behavior Regulation Intervention Specialist (EC-SEBRIS) graduate level certificate program was created to strengthen early care and education providers with the knowledge and practice of how to support emotion and behavior regulation in young children in their groups. Evaluation data provide evidence that early care and education professionals increased in their perception of self-efficacy and in their sensitivity of care and skills to support behavioral health in young children. Results indicated that the children in their care showed less challenging behaviors and increased social competencies. This manuscript highlights the importance of prevention and the dire need to provide young children with high-quality, appropriate care to support their mental health.

Testing the impact of a social skill training versus waiting list control group for the reduction of disruptive behaviors and stress among preschool children in child care: the study protocol for a cluster randomized trial

Background

Most preschoolers growing up in western industrialized countries receive child care services (CCS) during the day, while their parents are at work. Meta-analytic data suggest that CCS represent a stressful experience for preschoolers. This may be because preschoolers have not yet developed the social skills necessary to cope with the new and rapidly fluctuating social contexts of CCS. We tested the effectiveness of a child care-based social skill training program aiming to improve children’s social behaviors and reduce the stress they experience.

Method and design

We used a cluster randomized control trial (cRCT) to compare children’s social behaviors and stress levels in pre- and post-intervention according to whether they received a social skill training intervention or not. Nineteen (n = 19) public CCS (n = 362, 3-years-old preschoolers) of underprivileged neighborhoods (Montreal, Canada) were randomized to one of two conditions: 1) social skills training (n = 10 CCS); or 2) waiting list control group (n = 9 CCS). Educators in the intervention group conducted bi-weekly social skills training sessions over a period of 8 months. The intervention covered four topics: making social contacts, problem solving, emotional self-regulation, as well as emotional expression and recognition. Main outcome measures included preschoolers’ disruptive (e.g. aggression, opposition, conflicts) and prosocial behaviors (e.g. sharing toys, helping another child), and stress levels assessed by salivary cortisol sampling at pre and post intervention assessments. Educators’ practices will be tested as potential mediators of the expected changes in behaviors and neuroendocrine stress.

Discussion

To our knowledge, this is the first cRCT to test the effectiveness of a child care based social skill training program on the reduction of disruptive behaviors and levels of stress. Significant challenges include the degree of adherence to the intervention protocol as well educators and preschoolers’ turnover.

Trial registration

Current clinical trial number is ISRCTN84339956 (Ongoing study, Retrospectively registered on March 2017) No amendment to initial protocol.

Electronic supplementary material

The online version of this article (doi:10.1186/s40359-017-0197-9) contains supplementary material, which is available to authorized users.

The effect of a maternal history of childhood abuse on adrenocortical attunement in mothers and their toddlers

We investigated circadian mother-child adrenocortical attunement in the context of a maternal history of childhood abuse (HoA). Mothers were screened after birth using the Childhood Trauma Questionnaire. Women reporting moderate or severe abuse formed the HoA group (n = 37; HoAG) and were compared with a non-maltreated comparison group (n = 45; CG). Three years later, cortisol awakening response (CAR) and diurnal slope (DSL) were assessed. Mother-child interaction was coded using the Emotional Availability Scales at 12 months of age. For the CAR, we found adrenocortical attunement only in the HoAG (2-way interaction: p = .004), particularly if mothers scored low on structuring (3-way interaction: p = .042) and children scored low on responsiveness (3-way interaction: p = .044). DSL-attunement was dependent on maternal sensitivity (3-way interaction: p = .012) and child involvement (3-way interaction: p = .012). In the context of a maternal HoA, it seems possible for mother-child-dyads to show less optimal interactional quality but be stronger attuned to each other biologically.

Transition to Kindergarten: Negative Associations between the Emotional Availability in Mother-Child Relationships and Elevated Cortisol Levels in Children with an Immigrant Background

Background: The transition to child care is a challenging time in a child's life and leads to elevated levels of cortisol. These elevations may be influenced by the quality of the mother-child relationship. However, remarkably little is known about cortisol production in response to the beginning of child care among children-at-risk such as children with an immigrant background. However, attending kindergarten or any other child day-care institution can for example have a compensating effect on potential language deficits thus improving the educational opportunities of these children. Method: Data of a subsample of N = 24 "hard-to-reach" mother-child dyads was collected in the context of the psychoanalytic early prevention project FIRST STEPS. The project focuses on the earliest integration of children with an immigrant background by supporting parenting capacities in the critical phase of migration and early parenthood. Children's hair cortisol concentration (HCC) was assessed 1 week before (mean age = 38.77 months) and 3 months after kindergarten entry (mean age = 42.26 months). Hair analysis was conducted for both times of measurement, reflecting the first 3 months after kindergarten entry and 3 months prior. Furthermore, the emotional quality of the mother-child relationship was assessed with the help of the Emotional Availability Scales (EAS; Biringen, 2008) shortly before kindergarten entry when the children were about 3 years old (mean age = 37.2). Results and Conclusion: Children's mean cumulated HCC was higher after kindergarten entry than before. The increase correlated negatively with several dimensions of the EAS. Repeated measures ANCOVA revealed that particularly responsive children and children who had experienced less intrusive mother-child relationships demonstrated lower elevations in HCC after kindergarten entry. Furthermore, a decreased EA score was found in all EA dimensions, besides the dimension "mother's non-hostility," indicating problematic EA within the mother-child relationships of the sample. The results suggest that children with an immigrant background who experience more emotional available mother-child relationships seem to regulate stress induced by kindergarten entry more effectively, indicated by lower cortisol elevations after entry. This implicates that supporting early mother-child relationships by intervention may have a positive effect on the children's ability to regulate stress induced by kindergarten entry thus promoting child development.

Associations between stress biology indicators and overweight across toddlerhood

Biological stress responses are proposed as a pathway through which stress exposure can "get under the skin" and lead to health problems, specifically obesity. Yet, it is not clear when such associations may emerge or whether they are bidirectional. Cortisol and salivary alpha amylase (sAA) were considered indicators of the biological stress response. We tested the longitudinal association between cortisol and sAA and weight in 215 low-income children at ages 21, 27, and 33 months (52% male; 46% non-Hispanic white). sAA and cortisol intercept and slope (representing morning level and rate of change across the day) were calculated for each age point using random effect models. Children were weighed and length measured and categorized as overweight versus normal weight (overweight defined as weight-for-length z-score ≥85th percentile for age and sex). Cross-lagged models stratified by sex and controlling for birthweight z-score tested the concurrent and cross-lagged associations between each of 4 indices of stress biology individually (cortisol and sAA intercept and slope) and overweight. Overweight status was correlated across time. Cortisol and sAA were correlated across occasions of measurement, though somewhat less strongly in boys. There were no concurrent associations between stress indicators and overweight. sAA at 27 months predicted greater risk of overweight at 33 months in girls, such that both lower sAA intercept and more rapidly increasing sAA at 27 months predicted greater risk of overweight at 33 months (β=-0.64, p<0.05 and β=1.09, p<0.05, respectively). For boys only, overweight at 21 months predicted lower sAA intercept at 27 months (β=-0.35, p<0.05). Findings suggest that longitudinal associations of stress biology and weight status may be present only on a limited basis very early in the lifespan.

Children's physiological responses to childcare

This review focuses on children's physiological responses to out-of-home childcare. The finding that children's cortisol levels are higher at childcare than at home has been well-replicated. Here we summarize recent evidence examining possible correlates of elevated cortisol levels. Reviewed studies suggest that childcare quality matters, whereas group sizes and type of care do not. As for child characteristics, elevated cortisol at childcare is more pronounced in toddlers than in infants, and in inhibited and aggressive children. We discuss recent advances focusing on hair cortisol analysis and immunomarkers of stress, and suggest that there is a need for experimental and longitudinal studies to examine causal relations and possible negative long-term consequences for children's health and development.

Fifteen-month-old infants' cortisol levels decrease after a 30-min-warm-up procedure

Stress-induction procedures designed to increase cortisol levels in infants have been ineffective in many studies. One reason might be that infants did not have sufficient time to settle into the laboratory environment prior to the start of the stress induction, and thus already had high baseline levels of cortisol. In this study we investigate whether an extended warm-up period reduces infants' (N=22) cortisol levels. Fifteen-month-old infants' saliva cortisol was measured upon arrival at the laboratory. Then, they were allowed to play with their parent. After 30min, cortisol was measured again. There was a decrease in cortisol after 30min of free play. Our study suggests that infants' cortisol levels decrease when infants have the opportunity to acclimatize to the test environment. An extended warm-up phase prior to stress induction procedures might be necessary to reliably increase cortisol levels in infants.

Psychosocial Influences on Acceptability and Feasibility of Salivary Cortisol Collection From Community Samples of Children

Salivary cortisol is considered to be a safe and noninvasive measure of hypothalamic-pituitary-adrenal axis functioning, and is a commonly measured biomarker of the human stress response in pediatric research. However, cortisol is highly variable and sensitive to a wide range of factors, creating a challenge for reliable salivary cortisol collection in the community setting. Furthermore, the acceptability of salivary cortisol collection in community samples of children is largely unknown. The purpose of this integrative review was to investigate current evidence on the acceptability and feasibility of salivary cortisol collection in community samples of children. In an analysis framed by the Theory of Planned Behavior, data extracted from 31 studies revealed six categories of psychosocial influences on acceptability and feasibility: uncertainty and misconceptions, cultural and ethnic values, family rules and values, difficulty following protocols and procedures, burden of multiple samples, and child refusal or resistance. Further research is required to fully understand the factors that influence acceptability and feasibility of salivary cortisol collection in community samples of children. Understanding individual, family, and community perceptions of biobehavioral research will lead to more culturally sensitive and feasible community-based research methods. © 2016 Wiley Periodicals, Inc.

Child Care and Cortisol Across Infancy and Toddlerhood: Poverty, Peers, and Developmental Timing

Evidence suggests that relations between child care and children's development-behaviorally and physiologically-likely differ between children from high-versus low-risk contexts. Using data from the Family Life Project (N = 1,155), the authors tested (a) whether within- and between-child differences in children's child care experiences (i.e., quantity, type, caregiver responsivity, and peer exposure) were predictive of their cortisol levels across infancy and toddlerhood and (b) whether these relations differed for children experiencing different levels of environmental risk. They found some evidence of such interactive effects. For children from high-risk contexts, within-child increases in child care hours were predictive of cortisol decreases. The inverse was evident for children from low-risk contexts. This relation grew across toddlerhood. Whereas a history of greater center-based child care was predictive of heightened cortisol levels for low-risk families, this was not the case for children from high-risk families. Irrespective of risk, greater peer exposure (between children) was associated with lower cortisol levels.

Cortisol levels of infants in center care across the first year of life: links with quality of care and infant temperament

Cortisol concentrations of older children in childcare centers have been found to be higher than at home. This study focuses on infant cortisol in childcare centers throughout the first year of life, and aims to investigate whether inter-individual differences can be explained by temperament, the quality of maternal behavior, and the quality of center care. Sixty-four infants were followed for 9 months after entering care at 3 months of age. Salivary samples were taken at 10.00 h and 16.00 h in center care (in post-entry weeks 1, 2, 3, 4, 8, 12, 16, 24, and 36) and at home (in post-entry weeks 1, 24, and 36). Prior to entry, mothers completed a temperament questionnaire and the quality of maternal behavior (sensitivity and cooperation) was observed during routine bathing sessions. Subsequently, the infants were visited three times at center care to observe the quality of infant's interactive experiences with their professional caregiver. Longitudinal regression models showed that both morning and afternoon cortisol were higher in center care compared to home. Longitudinal regression models showed that infants receiving higher quality of maternal behavior displayed higher morning cortisol in center care, compared to infants receiving lower quality of maternal behavior. Higher quality of maternal behavior was also related to higher afternoon cortisol in center care, but only in infants high in negative emotionality. Center care quality was not related to cortisol. In sum, young infants show higher cortisol concentrations in center care that are related to infant temperament and quality of maternal behavior at home.

The Impact of Program Structure on Cortisol Patterning in Children Attending Out-of-Home Child Care

Full-day center-based child care has repeatedly been associated with rising levels of cortisol, a hormone that helps the body manage challenge, across the day at child care. This article presents findings from two studies examining the relationship between child care program structure (number of days per week, and hours per day) and cortisol production across the day. Study 1 presents findings comparing cortisol production in 3- to 5-year-old children enrolled in either full-day (N = 55) or half-day (N = 63) Head-Start-funded programs. Study 2 presents findings comparing young children enrolled in either full-day full-time (5 days per week; N = 37) or full-day part-time (2-3days/week; N = 41) primarily tuition-funded programs. Using multilevel modeling and controlling for a number of child factors, attending full-day, full-time programs (as compared to either half-day or part-time programs) was associated with increased cortisol production across the day on child care and home days. Implications for early childhood educators are discussed.

The cortisol awakening response (CAR) in toddlers: Nap-dependent effects on the diurnal secretory pattern

INTRODUCTION

Cortisol levels in adults show a sharp decrease from mid-morning to mid-afternoon. Most toddlers take afternoon naps, which is associated with a less mature diurnal pattern characterized by a midday plateau in cortisol secretion. Napping in preschoolers produces a robust cortisol awakening response (CAR), which may account for such maturational differences. This experimental study extends prior work by examining whether the presence and timing of the nap-dependent CAR influences the diurnal cortisol pattern in toddlers.

METHODS

Toddlers (n = 28; 13 females; 30-36 months) followed a strict biphasic sleep schedule (≥ 12.5h time in bed; ≥ 90 min nap) for ≥ 3 days before each of four randomly ordered, in-home cortisol assessments. For each assessment, saliva samples were obtained at morning awakening, ∼ 09:30, pre-nap, 0, 15, 30, 45, 90, and 135 min post-nap awakening (verified with actigraphy), and ∼ 19:30. On one day, children napped at their scheduled time, and parents collected saliva samples. On another day, children missed their nap, and parents collected saliva samples at matched times. On two other days, children napped 4h (morning) and 7h (afternoon) after awakening in the morning, during which time researchers collected pre- and post-nap saliva samples. Saliva was assayed for cortisol (μg/dl).

RESULTS

Three-level multilevel models were used to estimate the CAR and diurnal cortisol patterns in all four conditions. Compared to the no-nap condition (no observed CAR; b = -0.78, p = 0.65), we found a pronounced cortisol rise following the morning nap (b = 11.00, p < 0.001) and both afternoon naps whether samples were collected by parents (b = 5.19, p < 0.01) or experimenters (b = 4.97, p < 0.01). Napping in the morning resulted in the most robust post-nap cortisol rise (b = 10.21, p < 0.001). Diurnal patterns were analyzed using piecewise growth modeling that estimated linear coefficients for five separate periods throughout the day (corresponding to morning decline, noon decline, post-nap rise, post-nap decline, and evening decline). We observed a significant post-nap rise in cortisol values on the parent-collected afternoon nap (b = 3.41, p < 0.01) and the experimenter-collected morning nap (b = 7.50, p < 0.01) days as compared to the no-nap day (b = -0.17, p = 0.82). No other differences in diurnal profiles were observed between the parent-collected nap and no-nap conditions; however, toddlers had a steeper evening decline on the day of the morning nap compared to the parent-collected afternoon nap (b = 0.30, p < 0.05) and no-nap conditions (b = 0.27, p < 0.05).

DISCUSSION

These well-controlled findings suggest that the presence and timing of daytime naps influence the pattern of diurnal cortisol secretion in toddlers. They also provide support for the hypothesis that napping is the primary state driving the immature midday plateau in cortisol secretion, which becomes more adult-like across childhood. Prior studies of the diurnal cortisol pattern have employed a cubic model, and therefore, have not detected all possible variations due to napping. Our experimental data have important methodological implications for researchers examining associations between the slope of the diurnal cortisol pattern and developmental outcomes, as well as those utilizing afternoon cortisol reactivity protocols in napping children.

Emotional reactivity and parenting sensitivity interact to predict cortisol output in toddlers

Cortisol output in response to emotion induction procedures was examined at child age 24 months in a prospective longitudinal sample of 1,292 children and families in predominantly low-income and nonurban communities in two regions of high poverty in the United States. Multilevel analysis indicated that observed emotional reactivity to a mask presentation but not a toy removal procedure interacted with sensitive parenting to predict cortisol levels in children. For children experiencing high levels of sensitive parenting, cortisol output was high among children exhibiting high emotional reactivity and low among children exhibiting low emotional reactivity. For children experiencing low levels of sensitive parenting, cortisol output was unrelated to emotional reactivity.

Prenatal maternal stress predicts stress reactivity at 2½ years of age: the Iowa Flood Study

Prenatal maternal stress (PNMS) predicts psychosocial development in offspring. It has been hypothesized that during PNMS, glucocorticoids pass the placenta, reaching the foetus, leading to a long-term reprogramming and dysregulation of the foetal hypothalamic-pituitary-adrenal (HPA) axis. However, results are inconsistent across PNMS studies. One problem may be the confounding of objective degrees of hardship due to the stressor and subjective degrees of distress in the mother. The present study investigated the association between objective and subjective PNMS due to a natural disaster, the June 2008 Iowa floods, and stress reactivity in the offspring at 2½ years of age. Women who were pregnant during the floods were recruited, on average, within three months of the floods and their stress levels assessed. Mothers and their toddlers (n = 94 dyads) participated in a brief mother-toddler separation to induce physiological stress responses in the offspring. Salivary cortisol samples were collected four times during the procedure. We computed absolute change in cortisol (baseline to 20-minute post-stressor; baseline to 45-minute post-stressor) and Area Under the Curve with respect to increase and ground (AUCi; AUCg). Objective and subjective PNMS were positively correlated with AUCi, as was timing in gestation: the later in pregnancy the exposure occurred, the greater the cortisol increase. Controlling for objective hardship and other covariates, sex-by-subjective PNMS interactions showed a significant and positive association between subjective PNMS and Absolute Increase (45 min) and AUCi in females only, with little effect in males. These results suggest that PNMS leads to long-term alterations in the functioning of the HPA axis, evident as early as 30-months of age.

School readiness and self-regulation: a developmental psychobiological approach

Research on the development of self-regulation in young children provides a unifying framework for the study of school readiness. Self-regulation abilities allow for engagement in learning activities and provide the foundation for adjustment to school. A focus on readiness as self-regulation does not supplant interest in the development of acquired ability, such as early knowledge of letters and numbers; it sets the stage for it. In this article, we review research and theory indicating that self-regulation and consequently school readiness are the product of integrated developmental processes at the biological and behavioral levels that are shaped by the contexts in which development is occurring. In doing so, we illustrate the idea that research on self-regulation powerfully highlights ways in which gaps in school readiness and later achievement are linked to poverty and social and economic inequality and points the way to effective approaches to counteract these conditions.

School readiness and self-regulation: a developmental psychobiological approach

Research on the development of self-regulation in young children provides a unifying framework for the study of school readiness. Self-regulation abilities allow for engagement in learning activities and provide the foundation for adjustment to school. A focus on readiness as self-regulation does not supplant interest in the development of acquired ability, such as early knowledge of letters and numbers; it sets the stage for it. In this article, we review research and theory indicating that self-regulation and consequently school readiness are the product of integrated developmental processes at the biological and behavioral levels that are shaped by the contexts in which development is occurring. In doing so, we illustrate the idea that research on self-regulation powerfully highlights ways in which gaps in school readiness and later achievement are linked to poverty and social and economic inequality and points the way to effective approaches to counteract these conditions.