Are cortisol concentrations in human breast milk associated with infant crying?

The present longitudinal study is the first to investigate the association between human breast milk cortisol and infant crying over the first three months of life. Higher concentrations of breast milk cortisol were expected to be differentially associated with fussing and crying in boys and girls. At 2, 6, and 12 weeks of infant age, mothers (N = 70) collected a morning sample of their milk and kept a 3-day diary to measure infant fussing and crying. Cortisol was extracted and quantified from milk samples. Results showed that breast milk cortisol concentrations increased from 2 weeks through 12 weeks of infant age. Milk cortisol was unrelated to the total duration, frequency, and bout length of infant fussing and crying for both boys and girls. Directions for future research aiming to extend our knowledge on the biology of milk cortisol in relation to infant behavior and development are discussed.

Effects of the Caregiver Interaction Profile Training on Caregiver-Child Interactions in Dutch Child Care Centers: A Randomized Controlled Trial.

BACKGROUND: Previous studies underscore the need to improve caregiver-child interactions in early child care centers. OBJECTIVE: In this study we used a randomized controlled trial to examine whether a 5-week video feedback training can improve six key interactive skills of caregivers in early child care centers: Sensitive responsiveness, respect for autonomy, structuring and limit setting, verbal communication, developmental stimulation, and fostering positive peer interactions. METHOD: A total of 139 caregivers from 68 early child care groups for 0- to 4-year-old children in Dutch child care centers participated in this RCT, 69 in the intervention condition and 70 in the control condition. Caregiver interactive skills during everyday interactions with the children were rated from videotape using the Caregiver Interaction Profile (CIP) scales at pretest, posttest, and follow-up 3 months after the posttest. RESULTS: Results at posttest indicate a significant positive training effect on all six caregiver interactive skills. Effect sizes of the CIP training range between d = 0.35 and d = 0.79. Three months after the posttest, caregivers in the intervention group still scored significantly higher on sensitive responsiveness, respect for autonomy, verbal communication, and fostering positive peer interactions than caregivers in the control group with effect sizes ranging between d = 0.47 and d = 0.70. CONCLUSIONS: This study shows that the quality of caregiver-child interactions can be improved for all six important caregiver skills, with a relatively short training program. Possible ways to further improve the training and to implement it in practice and education are discussed.

Fostering Emotion Expression and Affective Involvement with Communication Partners in People with Congenital Deafblindness and Intellectual Disabilities.

BACKGROUND: Recent studies have shown that it is possible to foster affective involvement between people with congenital deafblindness and their communication partners. Affective involvement is crucial for well-being, and it is important to know whether it can also be fostered with people who have congenital deafblindness and intellectual disabilities. METHODS: This study used a multiple-baseline design to examine whether an intervention based on the Intervention Model for Affective Involvement would (i) increase affective involvement between four participants with congenital deafblindness and intellectual disabilities and their 13 communication partners and (ii) increase the participants' positive emotions and decrease their negative emotions. RESULTS: In all cases, dyadic affective involvement increased, the participants' very positive emotions also increased and the participants' negative emotions decreased. CONCLUSION: The results indicate that communication partners of persons with congenital deafblindness and intellectual disabilities can be successfully trained to foster affective involvement.

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.

Infant attachment predicts bodily freezing in adolescence: evidence from a prospective longitudinal study.

Early life-stress, particularly maternal deprivation, is associated with long-lasting deviations in animals' freezing responses. Given the relevance of freezing for stress-coping, translational research is needed to examine the relation between insecure infant-parent attachment and bodily freezing-like behavior in humans. Therefore, we investigated threat-related reductions in body sway (indicative of freezing-like behavior) in 14-year-old adolescents (N = 79), for whom attachment security was earlier assessed in infancy. As expected, insecure (vs. secure) attachment was associated with less body sway for angry vs. neutral faces. This effect remained when controlling for intermediate life events. These results suggest that the long-lasting effects of early negative caregiving experiences on the human stress and threat systems extend to the primary defensive reaction of freezing. Additionally, we replicated earlier work in adults, by observing a significant correlation (in adolescents assessed as securely attached) between subjective state anxiety and reduced body sway in response to angry vs. neutral faces. Together, this research opens venues to start exploring the role of freezing in the development of human psychopathology.

Associations between maternal prenatal cortisol concentrations and child outcomes: A systematic review.

A frequently proposed mechanism underlying the link between maternal prenatal stress/anxiety and child outcomes is heightened concentrations of maternal cortisol. In this systematic review, empirical findings on associations between maternal prenatal cortisol concentrations and child outcomes (physical/health, cognitive/motor, psychological/behavioral, and cortisol) are summarized. The number of empirical studies that find significant associations between maternal prenatal cortisol and child outcomes is small, but the majority of the studies that do find associations show that maternal cortisol is related to altered child outcomes (e.g. more physical/health problems, lower cognitive/motor development, more psychological/behavioral problems, and higher child cortisol concentrations). Inspection of the studies reveals possible critical gestational periods for maternal cortisol to affect different child outcomes. The heterogeneity in study designs and cortisol assessment methods makes drawing strong conclusions premature. However, the fact that most studies did not find significant associations suggests that maternal cortisol may not to be the sole or even main underlying mechanism in the relation between maternal prenatal stress/anxiety and child outcomes. Limitations of the reviewed studies are discussed, and directions for future research and reporting strategies are provided.

Maternal prenatal stress is associated with the infant intestinal microbiota.

Maternal prenatal stress has been often associated with infant physical development and health, as well as psychological functioning and behavior. However, the mechanisms underlying these relations remain elusive. The goal of the present study was to prospectively investigate the development of the intestinal microbiota as a potential pathway linking maternal prenatal stress and infant health. The development of the infant intestinal microbiota was followed over the first 110 days after birth in a healthy cohort of 56 vaginally born Dutch infants. Additionally, the relation between infant intestinal microbiota and gastrointestinal and allergic symptoms was examined. Results showed that maternal prenatal stress, i.e., either reported stress or elevated basal maternal salivary cortisol concentrations or both, was strongly and persistently associated with the infants' microbiota composition as determined by a phylogenetic microarray. Infants of mothers with high cumulative stress (i.e., high reported stress and high cortisol concentrations) during pregnancy had significantly higher relative abundances of Proteobacterial groups known to contain pathogens (related to Escherichia, Serratia, and Enterobacter), and lower relative abundances of lactic acid bacteria (i.e., Lactobacillus, Lactoccus, Aerococcus) and Bifidobacteria, altogether characteristics of a potentially increased level of inflammation. Furthermore, this aberrant colonization pattern was related to more maternally reported infant gastrointestinal symptoms and allergic reactions. In conclusion, clear links were found between maternal prenatal stress and the infant intestinal microbiota and health. Although causality cannot be concluded, the results suggest a possible mechanism by which maternal prenatal stress influences the offspring development. These results suggest a potential for bacterial interventions to enhance offspring health and development in pregnant women with stress.

Does the arrival index predict physiological stress reactivity in children.

Knowledge about children's stress reactivity and its correlates is mostly based on one stress task, making it hard to assess the generalizability of the results. The development of an additional stress paradigm for children, that also limits stress exposure and test time, could greatly advance this field of research. Research in adults may provide a starting point for the development of such an additional stress paradigm, as changes in salivary cortisol and alpha-amylase (sAA) over a 1-h pre-stress period in the laboratory correlated strongly with subsequent reactivity to stress task (Balodis et al., 2010, Psychoneuroendocrinology 35:1363-73). The present study examined whether such strong correlations could be replicated in 9- to 11-year-old children. Cortisol and sAA samples were collected from 158 children (83 girls) during a 2.5-h visit to the laboratory. This visit included a 1-h pre-stress period in which children performed some non-stressful tasks and relaxed before taking part in a psychosocial stress task (TSST-C). A higher cortisol arrival index was significantly and weakly correlated with a higher AUCg but unrelated to cortisol reactivity to the stressor. A higher sAA arrival index was significantly and moderately related to lower stress reactivity and to a lower AUCi. Children's personality and emotion regulation variables were unrelated to the cortisol and sAA arrival indices. The results of this study do not provide a basis for the development of an additional stress paradigm for children. Further replications in children and adults are needed to clarify the potential meaning of an arrival index.

Need fulfillment, need importance, and depressive symptoms of residents over the first eight months of living in a nursing home.

BACKGROUND: Based on self-determination theory and adaptation theories, the study aim was to investigate the relationship between need fulfillment (of autonomy, relatedness, and competence), need importance, and depressive symptoms during the first months of living in a nursing home. METHODS: Eight-month longitudinal questionnaire study in which 75 persons newly admitted to units for physically frail residents participated at baseline. Twenty-three longitudinal participants were remaining at the third and final measurement wave. RESULTS: The results show a main effect of need fulfillment and an interaction effect of need fulfillment and need importance on depressive symptoms over time. A prototypical plot shows that residents with low need fulfillment had higher initial levels of depressive symptoms that decreased modestly over time, regardless of their need importance. Residents with high need fulfillment had lower initial levels of depressive symptoms, but their trajectories differed for participants with low and high need importance. Residents with low need importance started with lower levels of depressive symptoms but remained stable over time, whereas residents with high need importance had more depressive symptoms at T1 that decreased slightly over time. CONCLUSIONS: In general, depressive symptoms do not change over time. However, individual trajectories of depressive symptoms seem to depend on individual need fulfillment and need importance. The residents that consider need fulfillment to be highly important but experience low need fulfillment had higher initial levels of depressive symptoms that decreased modestly over time, although the level of depressive symptoms remained higher as compared to the other residents.

Acute psychosocial stress and children's memory.

We investigated whether children's performance on working memory (WM) and delayed retrieval (DR) tasks decreased after stress exposure, and how physiological stress responses related to performance under stress. About 158 children (83 girls; Mage = 10.61 years, SD = 0.52) performed two WM tasks (WM forward and WM backward) and a DR memory task first during a control condition, and 1 week later during a stress challenge. Salivary alpha-amylase (sAA) and cortisol were assessed during the challenge. Only WM backward performance declined over conditions. Correlations between physiological stress responses and performance within the stress challenge were present only for WM forward and DR. For WM forward, higher cortisol responses were related to better performance. For DR, there was an inverted U-shape relation between cortisol responses and performance, as well as a cortisol × sAA interaction, with concurrent high or low responses related to optimal performance. This emphasizes the importance of including curvilinear and interaction effects when relating physiology to memory.

The relation between gaze aversion and cortisol reactivity in middle childhood.

The present study sought to investigate the relation between ethological observations of children's gaze aversion during a psychosocial stress task and their cortisol reactivity to the task, and how this relation might be moderated by how stressful the children perceived the stress task to be. Videos of 140 children (74 girls; Mage=10.60years) performing a psychosocial stress task in front of a jury were coded for displays of the children's gaze aversion from the jury, and saliva samples were taken to determine their cortisol reactivity. A questionnaire assessed the children's level of perceived stress. Results showed higher cortisol reactivity in children who perceived the task as more stressful. Furthermore, a quadratic relation between gaze aversion and cortisol was found which depended on the level of perceived stress: for children with low levels of perceived stress, cortisol reactivity was lowest with intermediate levels of gaze aversion, whereas for children with high levels of perceived stress cortisol reactivity was highest at intermediate levels of gaze aversion. The results suggest a modest association between subjective and physiological stress responses in 9- to 11-year-olds, and indicate that gaze aversion may play only a minor role as a behavioural coping strategy at this age.

Cortisol regulation in 12-month-old human infants: associations with the infants' early history of breastfeeding and co-sleeping.

Experiences during early life are suggested to affect the physiological systems underlying stress responses, including the hypothalamic-pituitary-adrenal axis (HPA axis). While stressful early experiences have been associated with dysregulated HPA-axis functioning, positive early experiences, i.e. high maternal caregiving quality, contribute to more optimal HPA-axis functioning. Influences of other early caregiving factors, however, are less well documented. The goal of this study was to examine whether breastfeeding and co-sleeping during the first 6 months of life were associated with infant cortisol regulation, i.e. cortisol reactivity and recovery, to a stressor at 12 months of age. Participants were 193 infants and their mothers. Information on breastfeeding and co-sleeping was collected using weekly and daily sleep diaries, respectively, for the first 6 months of life. Co-sleeping was defined as sleeping in the parents' bed or sleeping in the parents' room. At 12 months of age, infants were subjected to a psychological stressor [Strange Situation Procedure (SSP); Ainsworth et al. 1978]. Salivary cortisol was measured prestressor and at 25, 40, and 60 min poststressor to measure reactivity and recovery. Regression analyses showed that after controlling for maternal sensitivity, infant attachment status, feeding, and sleeping arrangements at 12 months of age and other confounders, more weeks of co-sleeping predicted lower infant cortisol reactivity to the SSP. Also, more weeks of breastfeeding predicted quicker cortisol recovery. These results indicate that an early history of co-sleeping and breastfeeding contributes positively to cortisol regulation in 12-month-olds.

Need fulfillment in the nursing home: resident and observer perspectives in relation to resident well-being.

Self-reports in nursing homes generally show highly satisfied residents, whereas observational studies provide more nuanced results. In this study, which is based on self-determination theory, the perspective of nursing home residents (self-reports) is compared to the perspective of trained "neutral" observers (video-observations). The experiences of physically frail older residents are measured with regard to the fulfillment of their needs for relatedness, autonomy, and competence. Self-reports of need fulfillment in general, in the caring relationship, and during a caregiving episode recorded on videotape of 36 residents (64 % female, mean age 80 years) were compared with observer ratings of resident need fulfillment during the latter caregiving episode. Furthermore, it was investigated which measure relates best to residents' self-reported well-being. The results show that residents rate their need fulfillment higher than observers. There is weak to moderate agreement between resident and observer ratings. Furthermore, only residents' self-reported need fulfillment in general is related with self-reported well-being. Different explanations are provided, including the "barrier of happiness," the use of cognitive strategies, a change in identity and existing power relations. There seems to be a paradox in caregiving: Residents and their needs should be central, but because residents might adapt their needs and wishes it is hard to assess these. Suggestions for practical applications are given.

The relation between emotion regulation strategies and physiological stress responses in middle childhood.

The current study sought to examine whether children's spontaneous use of the emotion regulation strategies suppression and reappraisal during a psychosocial stress task was related to their cortisol and alpha-amylase responses to that task. Salivary cortisol and alpha-amylase responses to a psychosocial stress task were assessed in 158 10-year-old children (83 girls). The children completed a self-report questionnaire measuring use of reappraisal and suppression during the task. Results showed overall increases in cortisol and alpha-amylase in response to the stressor, with higher cortisol reactivity in girls than in boys. With regard to emotion regulation, more use of suppression was related to lower cortisol reactivity in girls, and lower alpha-amylase reactivity and quicker alpha-amylase recovery in all children. The use of reappraisal was not related to the children's cortisol or alpha-amylase responses. The current study is the first to investigate the relation between the spontaneous use of reappraisal and suppression, and physiological stress responses to a psychosocial stressor in children. Our results indicate that reappraisal and suppression are used and can be measured even in 10-year-olds. At this age reappraisal appears ineffective at down-regulating physiological responses, while suppression was related to lower physiological responses. For cortisol reactivity there was a sex difference in the relation with suppression, indicating the importance of including sex as a moderator variable in research studying stress reactivity and its correlates in this age group.

Early school outcomes for children of postpartum depressed mothers: comparison with a community sample.

Previous studies of the long-term effects of maternal postpartum depression (PPD) on child development have mostly focused on a limited set of outcomes, and have often not controlled for risk factors associated with maternal depression. The present study compared children of postpartum depressed mothers (n = 29) with children from a community sample (n = 113) in terms of a broad range of developmental outcomes in the early school period. Controlling for risk factors associated with maternal depression, we found that children of postpartum depressed mothers had lower ego-resiliency, lower peer social competence, and lower school adjustment than the community sample children. In addition, girls of postpartum depressed mothers showed lower verbal intelligence, and, unexpectedly, showed fewer externalizing problems than their counterparts in the community sample. Results show that children's capacities to deal with stress and interact with peers in the early school period may be particularly affected by their mothers' PPD.

Peer rejection and HPA activity in middle childhood: friendship makes a difference.

Exclusion and victimization by classmates were related to levels and diurnal change in cortisol in 97 fourth graders (53% boys, M = 9.3 years). Number and quality of friendships were considered as moderators. Salivary cortisol was collected 5 times daily on 2 school days. Excluded children had elevated cortisol levels at school and a flattened diurnal cortisol curve, suggesting hypothalamic-pituitary-adrenocortical (HPA) axis dysregulation. This effect was weaker for children with more friends or better friendships. Victimization was not associated with cortisol level or change. The results demonstrate the role of HPA activity in peer group processes and indicate that group and dyadic factors interact in predicting stress in the peer group.

Which preventive interventions effectively enhance depressed mothers' sensitivity? A meta-analysis.

Improving depressed mothers' sensitivity is assumed to be a key element in preventing adverse outcomes for children of such mothers. This meta-analysis examines the short-term effectiveness of preventive interventions in terms of enhancing depressed mothers' sensitivity toward their child and investigates what type of intervention is most effective. Thirteen interventions, reported in 10 controlled outcome studies, met the inclusion criteria (N = 918). Meta-analytic results showed a small to medium, significant mean effect size (g = 0.32) with large variation in individual effect sizes (-0.56-1.76). Interventions including baby massage were highly effective in improving maternal sensitivity (g = 0.85). In contrast, individual therapy for the mother proved ineffective in terms of improving maternal sensitivity (g = -0.00). Two other significant predictors of greater effect sizes were the inclusion of a support group and the use of a higher number of intervention methods; however, the significance of these results was largely accounted for by one single study. Our meta-analysis confirms that depressed mothers' sensitivity can be improved by preventive intervention and suggests that baby massage may be an effective intervention method to evoke short-term changes in maternal sensitivity. It is unclear whether these changes are maintained over time.

Long-term effects of a home-visiting intervention for depressed mothers and their infants.

BACKGROUND: Whereas preventive interventions for depressed mothers and their infants have yielded positive short-term outcomes, few studies have examined their long-term effectiveness. The present follow-up of a randomised controlled trial (RCT) is one of the first to examine the longer-term effects of an intervention for mothers with postpartum depression and their infants at school-age. In early infancy, the intervention was found effective in improving mother-infant interaction and the child's attachment to its mother. METHODS: Twenty-nine mother-child pairs who completed the intervention are compared with 29 untreated mother-child dyads as to the quality of maternal interactive behaviour and the child outcomes of attachment security to the mother, self-esteem, ego-resiliency, verbal intelligence, prosocial behaviour, school adjustment, and behaviour problems at age 5 (M=68 months). RESULTS: In the total sample no lasting treatment benefits were found, but in families reporting a higher number of stressful life events, children in the intervention group had fewer externalising behaviour problems as rated by their mothers than children in the control group. CONCLUSIONS: In the context of multiple stressful life events the intervention served as a buffer by preventing the development of externalising problems in the child. The results warrant cautious interpretation because of the relatively small sample size and differential attrition revealing the mothers that completed the follow-up assessment to have improved less on maternal sensitivity following the intervention than the mothers who did not participate in the follow-up.

Developmental stimulation in child care centers contributes to young infants' cognitive development.

This study examined whether the quality of caregiver behavior in child care centers contributes to infant cognitive development at 9 months of age. Sixty-four infants (34 boys) were observed with their primary caregivers in child care centers at 3, 6, and 9 months of age. Caregiver behavior was rated for sensitivity and for stimulation of infant development during one-to-one caregiving interactions. Infant cognitive development was assessed using the Bayley Scales of Infant Development-II (Mental Development Index). Higher levels of developmental stimulation in the centers predicted higher levels of infant cognitive development at 9 months, beyond infant cognitive development at 3 months (just before entering child care), parental education, and maternal sensitivity. The results suggest that even small increases in developmental stimulation provided in child care centers in the first year of life may foster infants' cognitive development.

Cortisol in the first year of life: normative values and intra-individual variability.

INTRODUCTION: Many studies have incorporated cortisol measurements when studying infant development, but descriptions of normal development of basal cortisol levels in large study populations are scarce. The present study aimed to establish norm values for infant basal cortisol levels and to examine the development of intra-individual variability in the first year of life. METHODS: More than 2500 cortisol samples were collected in 300 infants at three different ages. At each age four 1100h samples were collected to determine average cortisol levels and intra-individual variability. The development of basal cortisol levels and intra-individual variability was analyzed with multilevel growth curve modeling. RESULTS: Norm tables with 90 and 95% intervals are presented. Basal cortisol levels decreased gradually over the year. Intra-individual variability was relatively large and stable in the first half year but decreased towards the end of the year. CONCLUSIONS: The results of this study will aid researchers in evaluating cortisol data collected in early infancy. It also underscores the importance of taking intra-individual cortisol variability into account in studies involving infants.