Maternal stress beginning in infancy may sensitize children to later stress exposure: effects on cortisol and behavior

Effects of early maternal distress and parenting on the development of children's self-regulation and externalizing behavior

Emotional distress experienced by mothers increases young children's risk of externalizing problems through suboptimal parenting and child self-regulation. An integrative structural equation model tested hypotheses that mothers' parenting (i.e., low levels of inductive discipline and maternal warmth) would mediate adverse effects of early maternal distress on child effortful control, which in turn would mediate effects of maternal parenting on child externalizing behavior. This longitudinal study spanning ages 3, 6, and 10 included 241 children, mothers, and a subset of teachers. The hypothesized model was partially supported. Elevated maternal distress was associated with less inductive discipline and maternal warmth, which in turn were associated with less effortful control at age 3 but not at age 6. Inductive discipline and maternal warmth mediated adverse effects of maternal distress on children's effortful control. Less effortful control at ages 3 and 6 predicted smaller relative decreases in externalizing behavior at 6 and 10, respectively. Effortful control mediated effects of inductive discipline, but not maternal warmth, on externalizing behavior. Findings suggest elevated maternal distress increases children's risk of externalizing problems by compromising early parenting and child self-regulation.

Blunted stress cortisol reactivity and failure to acclimate to familiar stress in depressed and sub-syndromal children

Depressed adults have shown blunted or elevated cortisol reactivity in response to various forms of psychosocial stress. However, there have been few studies of cortisol reactivity in children who had early onset depression or a history of depression during the preschool-school period. The present study utilized a laboratory stress paradigm and collected salivary cortisol from preschoolers at baseline (ages 3-5 years) and 24-month follow-up (ages 5-7 years). Repeated-measures multivariate analyses of variance (MANOVAs) were used to compare cortisol reactivity to mild stress between children with Major Depressive Disorder (MDD), elevated symptoms of depression (sub-syndromal MDD), and healthy controls. For healthy children, a quadratic cortisol reactivity curve was found at baseline (n=73), which appeared flatter under similar stressful situations at follow-up (n=14), which may reflect acclimation to the paradigm. In contrast, children with MDD (n=46) and sub-syndromal MDD (n=76) showed a peak cortisol response to the novelty of lab arrival and then reduced and blunted responses to stressors at baseline. These cortisol responses persisted at follow-up in children with a history of MDD (n=41) or sub-syndromal MDD (n=73). These results suggest that the hypothalamic-pituitary-adrenal (HPA) axis shows a blunted response to stress and failed to acclimate to familiar stressful situations in depressed and sub-syndromal depressed children.

Early adversity, socioemotional development, and stress in urban 1-year-old children

OBJECTIVE

To determine demographic, maternal, and child factors associated with socioemotional (SE) problems and chronic stress in 1-year-old children.

STUDY DESIGN

This was a prospective, longitudinal, community-based study, which followed mother-infant dyads (n = 1070; representative of race, education, and income status of Memphis/Shelby County, Tennessee) from midgestation into early childhood. Child SE development was measured using the Brief Infant-Toddler Social and Emotional Assessment in all 1097 1-year-olds. Chronic stress was assessed by hair cortisol in a subsample of 1-year-olds (n = 297). Multivariate regression models were developed to predict SE problems and hair cortisol levels.

RESULTS

More black mothers than white mothers reported SE problems in their 1-year-olds (32.9% vs 10.2%; P < .001). In multivariate regression, SE problems in blacks were predicted by lower maternal education, greater parenting stress and maternal psychological distress, and higher cyclothymic personality score. In whites, predictors of SE problems were Medicaid insurance, higher maternal depression score at 1 year, greater parenting stress and maternal psychological distress, higher dysthymic personality score, and male sex. SE problem scores were associated with higher hair cortisol levels (P = .01). Blacks had higher hair cortisol levels than whites (P < .001). In the entire subsample, increased hair cortisol levels were associated with higher parenting stress (P = .001), lower maternal depression score (P = .01), lower birth length (P < .001), and greater length at 1 year of age (P = .003).

CONCLUSION

Differences in maternal education, insurance, mental health, and early stress may disrupt SE development in children. Complex relationships between hair cortisol level in 1-year-olds and maternal parenting stress and depression symptoms suggest dysregulation of the child's hypothalamic-pituitary-adrenal axis.

The roles of DNA methylation of NR3C1 and 11β-HSD2 and exposure to maternal mood disorder in utero on newborn neurobehavior

Exposure to maternal mood disorder in utero may program infant neurobehavior via DNA methylation of the glucocorticoid receptor (NR3C1) and 11β-hydroxysteroid dehydrogenase type 2 ( 11β-HSD-2), two placental genes that have been implicated in perturbations of the hypothalamic pituitary adrenocortical (HPA) axis. We tested the relations among prenatal exposure to maternal depression or anxiety, methylation of exon 1F of NR3C1 and 11β-HSD-2, and newborn neurobehavior. Controlling for relevant covariates, infants whose mothers reported depression during pregnancy and showed greater methylation of placental NR3C1 CpG2 had poorer self-regulation, more hypotonia, and more lethargy than infants whose mothers did not report depression. On the other hand, infants whose mothers reported anxiety during pregnancy and showed greater methylation of placental 11β-HSD-2 CpG4 were more hypotonic compared with infants of mothers who did not report anxiety during pregnancy. Our results support the fetal programming hypothesis and suggest that fetal adjustments to cues from the intrauterine environment, in this case an environment that could be characterized by increased exposure to maternal cortisol, may lead to poor neurodevelopmental outcomes.

Stress reactivity in war-exposed young children with and without posttraumatic stress disorder: Relations to maternal stress hormones, parenting, and child emotionality and regulation

The current study examined biomarkers of stress in war-exposed young children and addressed maternal and child factors that may correlate with children's stress response. Participants were 232 Israeli children aged 1.5–5 years, including 148 children exposed to continuous war. Similarly, 56 were diagnosed with posttraumatic stress disorder (PTSD) and 92 were defined as exposed-no-PTSD. Child cortisol (CT) and salivary alpha amylase (sAA), biomarkers of the hypothalamic–pituitary–adrenal and sympathetic–adrenal–medullary arms of the stress response, were measured at baseline, following challenge, and at recovery. Maternal CT and sAA, PTSD symptoms, and reciprocal parenting, and child negative emotionality and regulatory strategies were assessed. Differences between war-exposed children and controls emerged, but these were related to child PTSD status. Children with PTSD exhibited consistently low CT and sAA, exposed-no-PTSD displayed consistently high CT and sAA, and controls showed increase in CT following challenge and decrease at recovery and low sAA. Exposed children showed higher negative emotionality; however, whereas exposed-no-PTSD children employed comfort-seeking strategies, children with PTSD used withdrawal. Predictors of child CT included maternal CT, PTSD symptoms, low reciprocity, and negative emotionality. Findings suggest that high physiological arousal combined with approach strategies may be associated with greater resilience in the context of early trauma.

Childhood maltreatment is associated with altered fear circuitry and increased internalizing symptoms by late adolescence

Maltreatment during childhood is a major risk factor for anxiety and depression, which are major public health problems. However, the underlying brain mechanism linking maltreatment and internalizing disorders remains poorly understood. Maltreatment may alter the activation of fear circuitry, but little is known about its impact on the connectivity of this circuitry in adolescence and whether such brain changes actually lead to internalizing symptoms. We examined the associations between experiences of maltreatment during childhood, resting-state functional brain connectivity (rs-FC) of the amygdala and hippocampus, and internalizing symptoms in 64 adolescents participating in a longitudinal community study. Childhood experiences of maltreatment were associated with lower hippocampus-subgenual cingulate rs-FC in both adolescent females and males and lower amygdala-subgenual cingulate rs-FC in females only. Furthermore, rs-FC mediated the association of maltreatment during childhood with adolescent internalizing symptoms. Thus, maltreatment in childhood, even at the lower severity levels found in a community sample, may alter the regulatory capacity of the brain's fear circuit, leading to increased internalizing symptoms by late adolescence. These findings highlight the importance of fronto-hippocampal connectivity for both sexes in internalizing symptoms following maltreatment in childhood. Furthermore, the impact of maltreatment during childhood on both fronto-amygdala and -hippocampal connectivity in females may help explain their higher risk for internalizing disorders such as anxiety and depression.

Within-person coupling of changes in cortisol, testosterone, and DHEA across the day in adolescents

We comprehensively examined within-person and between-person associations between cortisol and DHEA and cortisol and testosterone across the day. Data are from a sample of 213 adolescents aged 11-16 (M = 13.7, SD = 1.5 years) from the Northeastern US who were oversampled for psychopathology symptoms. Six repeated measures of hormone levels across 3 days were used to test three specific questions of cortisol-DHEA and cortisol-testosterone associations within individuals (coupling) across the day, and one question of cortisol-DHEA and cortisol-testosterone diurnal slopes were associated between adolescents. Results consistently revealed positive cortisol-DHEA and cortisol-testosterone coupling across the day, often more pronounced in girls relative to boys. Cortisol and DHEA slopes were positively associated, whereas cortisol and testosterone were negatively associated between-adolescents. Findings suggest multiple mechanisms and highlight the multifaceted nature of associations of hormone changes during adolescence and importance of considering both axes for between- and within-person aspects of neuroendocrine development.

Psychological stress and hospitalization for childhood asthma-a nationwide cohort study in two Nordic countries

OBJECTIVE

Exposures to psychological stress in early life may contribute to the development or exacerbation of asthma. We undertook a cohort study based on data from several population-based registers in Denmark and Sweden to examine whether bereavement in childhood led to increased asthma hospitalization.

METHODS

All singleton children born in Denmark during 1977-2008 and in Sweden during 1973-2006 were included in the study (N=5,202,576). The children were followed from birth to the date of first asthma hospitalization, emigration, death, their 18(th) birthday, or the end of study (31 December 2007 in Sweden and 31 December 2008 in Denmark), whichever came first. All the children were assigned to the non-bereaved group until they lost a close relative (mother, father or a sibling), from when they were included in the bereaved group. We evaluated the hazard ratio (HR) of first hospitalization for asthma in bereaved children using Cox proportional hazards regression models, compared to those who were in the non-bereaved group. We also did a sub-analysis on the association between bereavement and first asthma medication.

RESULTS

A total of 147,829 children were hospitalized for asthma. The overall adjusted HR of asthma hospitalization in bereaved children was 1.10 (95% confidence interval (CI): 1.04-1.16), compared to non-bereaved children. The risk of asthma hospitalization was increased in those who lost a close relative at age of 14-17 years (HR=1.54, 95% CI: 1.23-1.92), but not in younger age groups. The association between bereavement and asthma hospitalization did not change over time since bereavement. In the sub-analysis in singleton live births during 1996-2008 recorded in the DMBR, bereavement was associated with a lower use of asthma medication (HR=0.87, 95% CI: 0.80-0.95).

CONCLUSIONS

Our data suggests that psychological stress following bereavement in late adolescence is associated with an increased risk of asthma hospitalization or lowers the threshold for asthma hospitalization.

Approaches to salivary cortisol collection and analysis in infants

Salivary cortisol is becoming more commonly utilized as a biologic marker of stress in observational studies and intervention research. However, its use with infants (12 months of age or younger) is less widespread and poses some special challenges to researchers. In order to decide on the most suitable collection procedure for salivary cortisol in infants, a number of criteria should be considered. This article will aid investigators interested in integrating salivary cortisol measurement into their research studies by presenting (1) an overview of the patterns of cortisol secretion in infancy including the development of diurnal rhythm and response to stress; (2) a comparison of the most commonly used approaches for collecting salivary cortisol samples in infants including cotton rope, syringe aspiration technique, filter paper, hydrocellulose microsponge, and the Salimetrics children's swab; (3) a discussion of the factors contributing to heightened cortisol variability in infancy and how these can be limited; (4) analytical issues associated with cortisol measurement; and (5) examples of criteria to consider when choosing a saliva sampling method and lab for conducting assays.

HPA axis reactivity in early childhood: associations with symptoms and moderation by sex

Sex differences in rates of internalizing disorders have been attributed in part to heightened sensitivity to stress in females. While the sex difference in disorder rates becomes most pronounced in adolescence, developmental research suggests that stress reactivity in girls may be related to elevated internalizing symptoms even in childhood. We therefore examined whether child sex moderated associations between symptoms of psychopathology and cortisol reactivity to a standardized stress task in 409 three-year-old community-dwelling children. Anxious symptoms were associated with elevated cortisol reactivity, but only in girls. Externalizing symptoms were unrelated to baseline cortisol or cortisol reactivity, and no evidence for moderation by child sex was found. Results suggest that cortisol reactivity to stress in early childhood has a sex-specific association with girls' internalizing symptoms.

The management of mood disorders in pregnancy: alternatives to antidepressants

The management of mood disorders during pregnancy is complex due to risks associated with medication use and risks associated with untreated depression. Antidepressant use during pregnancy is an exposure for the unborn child, and it currently remains unclear what long-term repercussions there might be from this exposure, though available data are reassuring. On the other hand, there are risks for both the mother and child of untreated depression during pregnancy. There is a real need for research into nonpharmacological strategies for the prevention of relapse of mood disorders in pregnant women who are off medications. We have reviewed a number of potential candidate interventions including psychotherapies, exercise, light box therapy (LBT), repetitive transcranial magnetic stimulation (rTMS), electroconvulsive therapy (ECT), holistic strategies, and nutritional and herbal supplements. Currently there is a lack of evidence supporting the use of such strategies in the prevention of depressive relapse during pregnancy, though most of these strategies have at least some support for their use in the treatment of a major depressive episode. Carefully conducted research using one or more of these strategies in women who want to discontinue antidepressants for pregnancy is sorely needed.

Infants at familial risk for depression show a distinct pattern of cortisol response to experimental challenge

BACKGROUND

The aim of the study was to examine the link between maternal depression and the infant's HPA axis functioning in relation to a sequence of emotional challenges at 12 months postpartum, while controlling for maternal anxiety disorder and general sociodemographic risk.

METHOD

Two hundred and fifty-seven infants whose mothers had been interviewed in pregnancy, as part of a prospective longitudinal study of a nationally representative sample of U.K. families, were individually tested in the laboratory and then observed during a simulated birthday party scenario. Three cortisol samples were taken over the course of 1½ h of afternoon testing.

RESULTS

The cortisol levels of infants whose mothers had no history of depression decreased significantly after individual testing, and rose again significantly in response to the birthday party challenge. In contrast, infants whose mothers had been diagnosed with depression before conception, during pregnancy or in the first 6 months postpartum showed no decrease from the initially elevated levels at entry to the laboratory and a less marked increase in response to the party.

LIMITATIONS

The study does not employ a traditional stress paradigm; instead it introduces a novel design to assess HPA axis functioning in relation to everyday emotional challenges.

CONCLUSIONS

The findings suggest that altered responses to mildly challenging events in infancy may be a marker for infants' familial risk for depressive illness.

Predicting developmental changes in internalizing symptoms: examining the interplay between parenting and neuroendocrine stress reactivity

In this study, we examined whether parenting and HPA-axis reactivity during middle childhood predicted increases in internalizing symptoms during the transition to adolescence, and whether HPA-axis reactivity mediated the impact of parenting on internalizing symptoms. The study included 65 children (35 boys) who were assessed at age 5, 7, and 11. Parenting behaviors were assessed via parent report at age 5 and 11. The child's HPA-axis reactivity was measured at age 7 via a stress task. Internalizing symptoms were measured via teacher reports at age 5 and 11. High maternal warmth at age 5 predicted lower internalizing symptoms at age 11. Also, high reported maternal warmth and induction predicted lower HPA-axis reactivity. Additionally, greater HPA-axis reactivity at age 7 was associated with greater increases in internalizing symptoms from age 5 to 11. Finally, the association between age 5 maternal warmth and age 11 internalizing symptoms was partially mediated by lower cortisol in response to the stress task. Thus, parenting behaviors in early development may influence the physiological stress response system and therefore buffer the development of internalizing symptoms during preadolescence when risk for disorder onset is high.

Epigenetic basis for the development of depression in children

The growing field of epigenetics and human behavior affords an unprecedented opportunity to discover molecular underpinnings of mental health disorders and pave the way for the development of preventive intervention programs. Maternal depression during pregnancy is a serious public health issue and leads to a 4-fold increase in the likelihood that the child will develop depression. We describe how mood disorders, particularly depression, may be shaped by early life stress, programming, and epigenetic processes and pathways showing how these processes could lead to depression in childhood. Implications of this approach to the study of mental health disorders for preventive interventions are discussed.

Factors associated with cortisol levels and health in 5-6-year-old children

OBJECTIVES

This study assesses the relationships between social context (family and inter-peer context), stress, and illness in 5-6-year-old children.

METHODS

To this end, data were collected on spontaneous social interpeer behavior; families provided data on stress, anxiety, and parental acceptance-rejection; and the children's pediatricians provided data relative to their health. Data on stress-related hormones (cortisol) were collected using saliva samples.

RESULTS

The results revealed that none of the variables examined were significantly related to illness development in the subjects in the sample group. Cortisol levels, however, were positively associated with a record of chronic or congenital illnesses, the manifestation of behaviors related to the search for leadership status in the group and the presence of stressful events in the family environment.

CONCLUSIONS

Despite finding no relationship between children's level of adrenocortical activity and the contracting or contingent development of diseases, we did find that chronic/congenital diseases may constitute a source of early stress in childhood. Certain conditions of uncertainty in the social context (family and interpeer) also seem to constitute different sources of stress.

Neonatal amygdala lesions alter basal cortisol levels in infant rhesus monkeys

The amygdala is mostly thought to exert an excitatory influence on the hypothalamic-pituitary-adrenal (HPA) axis, although its role regulating HPA basal tone is less clear, particularly during primate development. The current study examined the effects of neonatal amygdala lesions on basal HPA function and the postnatal testosterone (T) surge of rhesus monkeys reared with their mothers in large outdoor social groups. An early morning basal blood sample was collected at 2.5 months of age, whereas at 5 months samples were collected not only at sunrise, but also at mid-day and sunset to examine the diurnal rhythm of cortisol. At 2.5 months of age sham-operated males exhibited higher cortisol than females, but this sex difference was abolished by neonatal amygdalectomy, with lesioned males also showing lower basal cortisol than controls. Although neonatal amygdalectomy did not alter the postnatal T surge, there was a positive relationship between T and basal cortisol levels. At 5 months of age, neither the sex difference in cortisol, nor its correlation with T levels were apparent any longer. Instead, the diurnal cortisol rhythm of both males and females with amygdalectomy showed a blunted decline from mid-day to sunset compared to controls. These results indicate that neonatal amygdala damage alters basal HPA function in infant rhesus monkeys, affecting males only at early ages (at 2.5 months), while leaving the postnatal T surge intact, and resulting in a flattened diurnal rhythm in both genders at the later ages. Thus, the primate amygdala has a critical influence on the HPA axis in the first few months of life.

[Social inequalities in health, early child development and biological embedding]

This paper describes evidence that led to the concept of biological embedding and introduces approaches designed to elucidate its mechanisms and role. Biological embedding occurs when: experience gets under the skin and alters human biological and developmental processes; systematic differences in experience in different social environments in society lead to systematically different biological and developmental states; these differences are stable and long term; and, finally, they have the capacity to influence health, well-being, learning, or behavior over the life course. The concept of biological embedding emerged from insights in population health on the unique characteristics of socioeconomic gradients: ubiquity in poor and post-scarcity societies alike; gradient seen regardless of whether SES is measured by income, education or occupation; cutting widely across health, well-being, learning and behavior outcomes; replicating itself on new conditions entering society; and, often, showing that flatter gradients mean better overall societal outcomes. Most important, the gradient begins the life course as a gradient in developmental health, suggesting that the emergence of a multifaceted resilience/vulnerability early in life is the best place to look for evidence of biological embedding. In order to understand its character, the metaphor of the "archeology of biological embedding" has been used, wherein the surficial stratum of the "dig" is experience and behavior; the shallow stratum is organ system and cellular function; and the deep stratum is gene function. We are now ready to address the fundamental question of biological embedding: how do early childhood environments work together with genetic variation and epigenetic regulation to generate gradients in health and human development across the life course?

Differentiating disordered affect in children and adolescents with type 1 diabetes

BACKGROUND

There is evidence for increased risk of affective disorders (AD) in adults with type 1 diabetes however, the prevalence and characteristics of AD in young people with the condition is unclear. Comorbid AD in type 1 diabetes is associated with deleterious self-management, sub-optimal clinical indicators, reduced quality of life, poorer physical health, increased complications, increased high risk behaviours in adolescence and young adulthood, and earlier mortality. The present study investigated the prevalence and character of AD in young people with type 1 diabetes.

METHODS

The self-report PH-PANAS-C was employed in a cross-sectional, case-control design to identify and differentiate full-syndrome (FS) and subthreshold (St) levels of AD in 53 participants with type 1 diabetes (case) and 54 age-balanced controls (N=107; 7-18 yrs).

RESULTS

Case participants reported greater AD than controls. When differentiated, only anxiety was significantly more prevalent. Case participants reported less positive affect, and greater negative affect and autonomic arousal. Further, 1:3 case participants presented with St symptoms of AD.

LIMITATIONS

Self-report measures are known to produce moderated responses therefore symptoms may be more severe than reported. There has been some suggestion that responses to somatic items in the PH-PANAS-C may relate to diabetes-specific states rather than affect-related symptoms however, recent evidence has refuted this argument.

CONCLUSIONS

AD, particularly anxiety, represents a significant clinical concern in young people with type 1 diabetes both as a disorder in its own right and as a major impediment to primary care and management of the diabetes. The significant dominance of anxiety-related symptoms and prevalence of subthreshold presentation warrant further investigation.

Family psychological stress early in life and development of type 1 diabetes: the ABIS prospective study

AIMS

This study investigated whether psychological stress in the family during the child's first year of life are associated with the risk of childhood type 1 diabetes (T1D). According to the beta-cell stress hypothesis all factors that increase the need for, or the resistance to, insulin may be regarded as risk factors for T1D.

METHODS

Among 8921 children from the general population with questionnaire data from one parent at child's birth and at 1 year of age, 42 cases of T1D were identified up to 11-13 years of age. Additionally 15 cases with multiple diabetes-related autoantibodies were detected in a sub-sample of 2649 children.

RESULTS

Cox regression analyses showed no significant associations between serious life events (hazard ratio 0.7 for yes vs. no [95% CI 0.2-1.9], p=0.47), parenting stress (0.9 per scale score [0.5-1.7], p=0.79), or parental dissatisfaction (0.6 per scale score [0.3-1.2], p=0.13) during the first year of life and later diagnosis of T1D, after controlling for socioeconomic, demographic, and diabetes-related factors. Inclusion of children with multiple autoantibodies did not alter the results.

CONCLUSIONS

No association between psychological stress early in life and development of T1D could be confirmed.

Association of maternal exposure to childhood abuse with elevated risk for autism in offspring

IMPORTANCE

Adverse perinatal circumstances have been associated with increased risk for autism in offspring. Women exposed to childhood abuse experience more adverse perinatal circumstances than women unexposed, but whether maternal abuse is associated with autism in offspring is unknown.

OBJECTIVES

To determine whether maternal exposure to childhood abuse is associated with risk for autism in offspring and whether possible increased risk is accounted for by a higher prevalence of adverse perinatal circumstances among abused women, including toxemia, low birth weight, gestational diabetes, previous induced abortion, intimate partner abuse, pregnancy length shorter than 37 weeks, selective serotonin reuptake inhibitor use, and alcohol use and smoking during pregnancy.

DESIGN AND SETTING

Nurses' Health Study II, a population-based longitudinal cohort of 116 430 women.

PARTICIPANTS

Nurses with data on maternal childhood abuse and child's autism status (97.0% were of white race/ethnicity). Controls were randomly selected from among children of women who did not report autism in offspring (participants included 451 mothers of children with autism and 52 498 mothers of children without autism).

MAIN OUTCOME MEASURES

Autism spectrum disorder in offspring, assessed by maternal report and validated with the Autism Diagnostic Interview-Revised in a subsample.

RESULTS

Exposure to abuse was associated with increased risk for autism in children in a monotonically increasing fashion. The highest level of abuse was associated with the greatest prevalence of autism (1.8% vs 0.7% among women not abused, P = .005) and with the greatest risk for autism adjusted for demographic factors (risk ratio, 3.7; 95% CI, 2.3-5.8). All adverse perinatal circumstances except low birth weight were more prevalent among women abused in childhood. Adjusted for perinatal factors, the association of maternal childhood abuse with autism in offspring was slightly attenuated (risk ratio for highest level of abuse, 3.0; 95% CI, 1.9-4.8).

CONCLUSIONS AND RELEVANCE

We identify an intergenerational association between maternal exposure to childhood abuse and risk for autism in the subsequent generation. Adverse perinatal circumstances accounted for only a small portion of this increased risk.

Exploring patterns in cortisol synchrony among anxious and nonanxious mother and child dyads: a preliminary study

Given that anxiety is highly familial, the current pilot study explored the association between anxiety diagnosis and diurnal cortisol rhythm in mother-child dyads with the hypothesis that a predisposition toward homogenous cortisol profiles may partially explain the familial linkage of anxiety. The role of family environment in stress response was also examined. Participants were 27 mother-child dyads. Results indicated that patterns of cortisol secretion between mother and child are synchronous. Maternal anxiety and aspects of family functioning significantly predicted child awakening cortisol pattern. Further, affective involvement and gender of the child significantly predicted mother-child diurnal cortisol secretion synchrony. These findings provide support for the degree of synchrony in patterns of physiological responsiveness between mother and child, as well as the importance of a child's affective environment in the prediction of a diagnosis of anxiety.

Persistent household food insecurity, HIV, and maternal stress in peri-urban Ghana

Background

The mental health of caregivers has been shown to be important for improving HIV prevention and treatment. Household food insecurity affects hundreds of millions of individuals in Sub-Saharan Africa, a region that experiences a disproportionate burden of the HIV pandemic. Both maternal HIV diagnosis and household food insecurity may be linked with maternal stress. This in turn may lead to unhealthy coping behaviors. We examined the independent associations of HIV, persistent household food insecurity and the synergistic effect of both on maternal stress.

Methods

Ghanaian women recruited prenatally from hospitals offering voluntary counseling and testing (VCT) were followed for 12 months after childbirth (N = 232). A locally adapted 7-item version of the US Household Food Security Survey Module was applied at four time points postpartum. We dichotomized participant households as being persistently food insecure (i.e., food insecure at each time point) or not (i.e., food secure at any time point). We dichotomized participant women as not perceiving vs. perceiving stress at 12 months postpartum in reference to the median sample score on the 4-item Cohen’s stress scale. Binary multivariate logistic regression models were used to assess the independent and interactive effects of maternal HIV and persistent household food insecurity on maternal stress.

Results

The proportion of HIV-positive women that lived in severe food insecure households increased over time. By contrast, the HIV-negative group living in severely food insecure households experienced a steady decline across time. HIV-infection (AOR = 2.31, 95% CI 1.29-4.12) and persistent household food insecurity (AOR = 3.55, 95% CI 1.13-11.13) were independently associated with maternal stress in a multivariate model. Being both HIV-positive and persistently food insecure strongly and synergistically increased the risk for maternal perceived stress (AOR = 15.35, 95% CI 1.90-124.14).

Conclusion

In agreement with syndemic theory there is a powerful synergism between maternal HIV diagnosis and household food insecurity on maternal stress. Comprehensive multi-dimensional intervention studies are needed to better understand how to reduce stress among HIV-positive women living in persistently food insecure households and how to reduce the likelihood of food insecurity in HIV-affected households in Sub-Saharan Africa.

Parenting stress and external stressors as predictors of maternal ratings of child adjustment

This study sought to disentangle the effects of different kinds of stress on maternal ratings of child externalizing and internalizing problems, social inhibition, and social competence, with a primary focus on parenting stress. The relations were explored in a sample consisting of mothers of 436 children (Mage  = 7 years) in Sweden. Half the sample had had early clinical contacts during infancy due to child regulation problems, and the rest were mothers without known such early contacts. Demographic factors, family stressors, and parenting stress were examined in stress - adjustment models. Family stressors were clinical contact during infancy, current child and parent health problems, recent negative life events, and insufficient social support. Parenting stress as a mediator of the effect of other stressors on rated child adjustment was tested as was social support as a moderator of the effect of parenting stress on adjustment. The results showed that a higher parenting stress level was associated with maternal ratings of more externalizing and internalizing behaviors, more social inhibition, and lower social competence. Other family stressors and background variables were also found to be of importance, mainly for externalizing and internalizing problems and to some extent for social competence. Social inhibition had a unique relation to parenting stress only. Parenting stress mediated effects of other stressors in twelve models, whereas social support had no moderating effect on the link between parenting stress and child adjustment. Thus, parenting stress seems to be an important overarching construct. Clinical implications are proposed.

Hair cortisol reflects socio-economic factors and hair zinc in preschoolers

This study examined the relationship between children's hair cortisol and socioeconomic status of the family, as measured by parental education and income. Low family socioeconomic status has traditionally been considered a long-term environmental stressor. Measurement of hair cortisol provides an integrated index of cumulative stress exposure across an extended period of time. The present study is the first to examine the relationship between hair cortisol and parental education as well as parental income in a representative sample of preschoolers. Data on hair cortisol, family income, and parental education were collected for a representative sample of 339 children (Mean age=4.6 years; SD=.5 years) from across 23 neighbourhoods of the city of Vancouver, Canada. As maternal education was shown previously to be associated with hair zinc level, hair zinc measurements were included as well in order to explore potential relationships between hair zinc and hair cortisol. The relationship between hair cortisol and parental education was examined using hierarchical regression, with hair zinc, gender, age, and single parenthood included as covariates. Maternal and paternal education both were correlated significantly with hair cortisol (r=-0.18; p=.001). The relationship remained statistically significant even after controlling for all demographic covariates as well as for hair zinc and after taking the neighbourhood-level clustering of the data into account. Parental income, on the other hand, was not related significantly to children's hair cortisol. This study provides evidence that lower maternal and paternal education are associated with higher hair cortisol levels. As hair cortisol provides an integrated index of cortisol exposure over an extended time period, these findings suggest a possibly stable influence of SES on the function of the hypothalamic-pituitary-adrenal (HPA) axis. Cumulative exposure to cortisol during early childhood may be greater in children from low socio-economic backgrounds, possibly through increased exposure to environmental stressors.

Epigenetic vestiges of early developmental adversity: childhood stress exposure and DNA methylation in adolescence

Fifteen-year-old adolescents (N = 109) in a longitudinal study of child development were recruited to examine differences in DNA methylation in relation to parent reports of adversity during the adolescents' infancy and preschool periods. Microarray technology applied to 28,000 cytosine-guanine dinucleotide sites within DNA derived from buccal epithelial cells showed differential methylation among adolescents whose parents reported high levels of stress during their children's early lives. Maternal stressors in infancy and paternal stressors in the preschool years were most strongly predictive of differential methylation, and the patterning of such epigenetic marks varied by children's gender. To the authors' knowledge, this is the first report of prospective associations between adversities in early childhood and the epigenetic conformation of adolescents' genomic DNA.

Epigenetic mechanisms for the early environmental regulation of hippocampal glucocorticoid receptor gene expression in rodents and humans

Parental care influences development across mammals. In humans such influences include effects on phenotypes, such as stress reactivity, which determine individual differences in the vulnerability for affective disorders. Thus, the adult offspring of rat mothers that show an increased frequency of pup licking/grooming (ie, high LG mothers) show increased hippocampal glucocorticoid receptor (GR) expression and more modest hypothalamic-pituitary-adrenal responses to stress compared with the offspring of low LG mothers. In humans, childhood maltreatment associates decreased hippocampal GR expression and increased stress responses in adulthood. We review the evidence suggesting that such effects are mediated by epigenetic mechanisms, including DNA methylation and hydroxymethylation across GR promoter regions. We also present new findings revealing associated histone post-translational modifications of a critical GR promoter in rat hippocampus. Taken together these existing evidences are consistent with the idea that parental influences establish stable phenotypic variation in the offspring through effects on intracellular signaling pathways that regulate the epigenetic state and function of specific regions of the genome.

Maternal social stress modulates the development of prepulse inhibition of startle in infants

BACKGROUND

Stress during rearing has negative effects on the maturation of information processing in rodent offspring, but similar evidence in humans is absent. Prepulse inhibition (PPI) of startle is a measure reflecting the integrity of information processing. PPI does not depend on active cooperation, making it a suitable measure for studying newborns and infants. This study investigated whether postnatal development of infant PPI is influenced by self-reported stress in the mother.

METHODS

49 healthy term-born infants were studied twice, four days after birth and again at four months. PPI was assessed by presentation of acoustic startle stimuli (95dB) either alone or preceded (SOA 120ms) by a prepulse (75dB). Mother's social stress levels were assessed with the modified Trier Inventory for the Assessment of Chronic Stress (TICS). Cortisol saliva samples were collected from mothers and their children.

RESULTS

ANOVA revealed a different development of PPI in infants whose mothers reported enhanced stress levels due to social isolation and reduced social recognition. Cortisol levels were related to mothers' self-report stress, but not to PPI development in infants.

CONCLUSIONS

Maternal stress experience has an impact on the maturation of human infants' information processing in the first four months after birth.

Understanding the relation of low income to HPA-axis functioning in preschool children: cumulative family risk and parenting as pathways to disruptions in cortisol

This study examined the relation of low income and poverty to cortisol levels, and tested potential pathways from low income to disruptions in cortisol through cumulative family risk and parenting. 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. Lower income was related to lower morning cortisol levels, and cumulative risk predicted a flatter diurnal slope, with a significant indirect effect through maternal negativity, suggesting that parenting practices might mediate an allostatic effect on stress physiology.

Developmental pathways to amygdala-prefrontal function and internalizing symptoms in adolescence

Early life stress (ELS) and function of the hypothalamic-pituitary-adrenal axis predict later psychopathology. Animal studies and cross-sectional human studies suggest that this process might operate through amygdala-ventromedial prefrontal cortex (vmPFC) circuitry implicated in the regulation of emotion. Here we prospectively investigated the roles of ELS and childhood basal cortisol amounts in the development of adolescent resting-state functional connectivity (rs-FC), assessed by functional connectivity magnetic resonance imaging (fcMRI), in the amygdala-PFC circuit. In females only, greater ELS predicted increased childhood cortisol levels, which predicted decreased amygdala-vmPFC rs-FC 14 years later. For females, adolescent amygdala-vmPFC functional connectivity was inversely correlated with concurrent anxiety symptoms but positively associated with depressive symptoms, suggesting differing pathways from childhood cortisol levels function through adolescent amygdala-vmPFC functional connectivity to anxiety and depression. These data highlight that, for females, the effects of ELS and early HPA-axis function may be detected much later in the intrinsic processing of emotion-related brain circuits.

Putting the concept of biological embedding in historical perspective

This paper describes evidence that led to the concept of biological embedding and research approaches designed to elucidates its mechanisms. Biological embedding occurs when experience gets under the skin and alters human biological and developmental processes; when systematic differences in experience in different social environments in society lead to systematically different biological and developmental states; when these differences are stable and long term; and, finally, when they have the capacity to influence health, well-being, learning, or behavior over the life course. Biological embedding emerged from insights in population health on the unique characteristics of socioeconomic gradients: Ubiquity in poor and postscarcity societies alike; gradient seen regardless of whether socioeconomic status is measured by income, education, or occupation; cutting widely across health, well-being, learning, and behavior outcomes; replicating itself on new conditions entering society; and, often, showing that flatter gradients mean better overall societal outcomes. Most important, the gradient begins the life course as a gradient in developmental health, suggesting that the emergence of a multifaceted resilience/vulnerability early in life is the best place to look for evidence of biological embedding. To understand its character, the metaphor of the "archeology of biological embedding" has been used, wherein the surficial stratum of the "dig" is experience and behavior, the shallow stratum is organ system and cellular function, and the deep stratum is gene function. We are now ready to address the fundamental question of biological embedding: How do early childhood environments work together with genetic variation and epigenetic regulation to generate gradients in health and human development across the life course?

How can the study of physiological reactivity contribute to our understanding of adversity and resilience processes in development?

The focus of this article is to present current progress in understanding the interplay among adversity, physiological sensitivity to context, and adaptive functioning, with an emphasis on implications and future directions for resilience researchers. It includes a review of current literature that demonstrates (a) links between various levels of adversity exposure and variability in physiological reactivity, (b) how the interplay between children's physiological reactivity and different sources of risk and adversity relates to variability in adaptive functioning, and (c) various approaches for capturing a more dynamic nature of physiological reactivity and related processes. Throughout, important conceptual and empirical issues are highlighted.

Caregiver Protective Behavior, Toddler Fear and Sadness, and Toddler Cortisol Reactivity in Novel Contexts

Previous research has shown that caregiver protective behavior may exacerbate toddler distress in specific contexts. The current study sought to extend this work to examine associations between these variables and toddler cortisol reactivity. Ninety-three 24-month-old toddlers were observed across six novel contexts designed to elicit distress. Toddlers were asked to give saliva samples at the beginning and end of the laboratory procedure. Toddler sadness, toddler fear, and caregiver protective behavior were coded. Results indicate that caregiver protective behavior accounted for the association between toddler sadness and cortisol reactivity where higher levels of protective behavior were associated with higher cortisol reactivity. The current study showed that caregiver protective behavior, which functions to prevent a child from interacting with a novel stimulus, is an important mechanism to consider when understanding toddler stress responses during novel contexts.

Timing matters: long term effects of adversities from prenatal period up to adolescence on adolescents' cortisol stress response. The TRAILS study

OBJECTIVE

Altered cortisol response is a vulnerability marker for a variety of stress-related diseases and psychiatric disorders. Childhood adversity has been shown to modify this response, but evidence is inconsistent. Effects may differ depending on the timing of exposure, or due to the interplay between pre/postnatal adversity and later adversities. The present study examined the influence of adversity during different timeframes (pre/postnatal, ages 0-5, 6-11, 12-13, 14-15 years), and the interaction between pre/postnatal and later adversity on adolescents' cortisol stress response.

METHOD

Four salivary cortisol samples were collected before and after a social stress test in 471 16-year-old adolescents from the longitudinal study TRAILS. Data on pre/postnatal exposure to adversities were obtained from Preventive Child Healthcare records and parental reports, subsequent adversities from parental and self-reports.

RESULTS

Pre/postnatal adversity was associated with increased cortisol reactivity. Adversities during ages 0-5 were not associated with cortisol outcomes. Adversities during ages 6-11 were associated with a high cortisol level, especially in those exposed to pre/postnatal adversity, while adversities during ages 12-13 and 14-15 were associated with a low cortisol level.

CONCLUSIONS

Results highlight the importance to take the timing of stress exposure into account. In addition to programming effects, pre/postnatal adversity interacts with childhood adversity in producing deviant cortisol levels. Puberty may be marked by a transition in how adversities affect the HPA-axis, with cortisol hypersecretion before age 11 and hyposecretion after age 11.

Transgenerational transmission of anxiety induced by neonatal exposure to lipopolysaccharide: implications for male and female germ lines

Neonatal lipopolysaccharide (LPS) exposure increases anxiety-like behaviour and alters neuroendocrine responses to stress in adult rats. The current study assessed whether this anxiety-related phenotype observed in rats neonatally exposed to LPS is transferable to subsequent generations. Wistar rats were exposed to LPS (0.05 mg/kg, Salmonella enteritidis) or non-pyrogenic saline (equivolume) on postnatal days 3 and 5. In adulthood, animals were subjected to restraint and isolation stress or no stress, and subsequently evaluated for anxiety-like behaviours on the elevated plus maze, acoustic startle response, and holeboard apparatus. Blood was collected to examine corticosterone responses to stress and behavioural testing in adulthood. Animals from both treatment groups which exhibited the anxiety-like phenotype were bred with untreated partners. Maternal care of the second generation (F2) was monitored over the first week of life. In adulthood, the F2 generation underwent identical testing procedures as the parental (F1) generation. The F2 offspring of females exposed to LPS as neonates exhibited an anxiety-like phenotype in adulthood and a potentiated corticosterone response to stress (p<.05). F2 offspring of males exposed to LPS as neonates also exhibited an anxiety-like phenotype (p<.05), however, no differences in corticosterone responses were observed. To determine the impact of maternal care on the anxiety-like phenotype, a cross-fostering study was conducted in which offspring of LPS-treated females were fostered to saline-treated mothers and vice versa, which was found to reverse the behavioural and endocrine phenotypes of the F2 generation. These data indicate that a neonatally bacterially induced anxiety phenotype is transferable across generations in both sexes. Maternal care is the mediating mechanism along the maternal line. We suggest that transmission may be dependent upon heritable epigenetic phenomena for the paternal line. The implications of this study apply to potential neuroimmune pathways through which psychopathology may be transmitted along filial lines.

Reducing behavioral inhibition to novelty via systematic neonatal novelty exposure: the influence of maternal hypothalamic-pituitary-adrenal regulation

BACKGROUND

Behavioral inhibition (BI) to novelty is thought to be a stable temperament type that appears early in life and is a major risk factor for anxiety disorders. In the rat, habituation of such inhibition can be facilitated via neonatal novelty exposure (NNE), thus reducing BI to novelty. Here, we tested the hypothesis that this early intervention effect is modulated by the context of maternal self-stress regulation.

METHODS

The NNE was carried out during postnatal days 1-21, in which one half of each litter was exposed to a relatively novel nonhome environment for 3-min daily while the remaining one half stayed in the home cage. After weaning, BI to novelty was assessed in an open field with a measure of disinhibition defined as a greater increase in exploration across two brief trials. Maternal context was characterized by trait measures of hypothalamic-pituitary-adrenal (HPA) axis reactivity, including basal and stress-evoked corticosterone (CORT) responses.

RESULTS

Family-to-family variations in the NNE effect were associated with variations in maternal HPA function-a low-basal CORT and high-evoked CORT response profile constituting the context for a novelty-induced facilitation of disinhibition (i.e., a greater increase in exploratory activity over repeated trials) and an opposite HPA profile constituting the context for a novelty-induced reduction of disinhibition.

CONCLUSIONS

This result is consistent with the hypothesis that maternal self-stress regulation modulates the effect of early life intervention on BI to novelty and suggests that effective interventions should include strategies to help mothers improve their self-stress regulation.

Longitudinal stability and developmental properties of salivary cortisol levels and circadian rhythms from childhood to adolescence

This study aimed to (1) identify a stable, trait-like component to cortisol and its circadian rhythm, and (2) investigate individual differences in developmental trajectories of HPA-axis maturation. Multiple salivary cortisol samples were collected longitudinally across four assessments from age 9 (3rd grade) through age 15 (9th grade) in a community sample of children (N = 357). Sophisticated statistical models examined cortisol levels and its rhythm over time; effects of age, puberty and gender were primarily considered. In addition to situation-specific and stable short-term or epoch-specific cortisol components, there is a stable, trait-like component of cortisol levels and circadian rhythm across multiple years covering the transition from childhood into adolescence. Youth had higher cortisol and flatter circadian rhythms as they got older and more physically developed. Girls had higher cortisol, stronger circadian rhythms, and greater developmental influences across adolescence. Distinguishing a stable, trait-like component of cortisol level and its circadian rhythm provides the empirical foundation for investigating putative mechanisms underlying individual differences in HPA functioning. The findings also provide important descriptive information about maturational processes influencing HPA-axis development.

Stress-related programming of autonomic imbalance: role in allergy and asthma

Evidence linking psychological stress to allergy has grown with our increased understanding of the natural history and pathophysiology of these disorders and the neurobiology of stress vulnerability. However, the specific pathways that increase vulnerability to developing allergy and associated disorders remain to be elucidated. Autonomic nervous system functioning (autonomic balance) has been implicated in allergy for some time albeit links between autonomic balance and immune function in early development have been under studied. Starting in utero, stress may influence the programming of brain neurotransmitter systems, sympathetic and parasympathetic nervous system functioning, and the hypothalamic-pituitary-adrenal axis, which in turn may alter neural regulation of immune function. Epigenetic dysregulation of gene expression may be a fundamental mechanism for programming of early neural-immune processes.

Human amygdala development in the absence of species-expected caregiving

In altricial species, like the human, caregiver presence is necessary for typical emotional development. Children who have been raised in institutional care early in life experience caregiver deprivation and are at significantly elevated risk for emotional difficulties. The current manuscript examines the non-human and human literatures on amygdala development following caregiver deprivation and presents an argument that in the absence of the species-expected caregiver presence, human amygdala development exhibits rapid development and perhaps premature engagement that results in some of the emotional phenotypes observed following early institutional care.

Effects of prenatal and postnatal parent depressive symptoms on adopted child HPA regulation: independent and moderated influences

This study used a prospective adoption design to investigate effects of prenatal and postnatal parent depressive symptom exposure on child hypothalamic-pituitary-adrenal (HPA) activity and associated internalizing symptoms. Birth mother prenatal symptoms and adoptive mother/father postnatal (9-month, 27-month) symptoms were assessed with the Beck Depression Inventory in a sample of 192 families as part of the Early Growth and Development adoption Study. Child morning/evening cortisol levels and child symptoms of internalizing disorders (according to mother/father report on the Child Behavior Checklist) were assessed at 54 months, and birth mother diurnal cortisol was measured at 48 months postnatal. Hierarchical linear modeling was used to test main effects and interactions of parents' symptoms predicting child cortisol, controlling for birth mother cortisol. Prenatal exposure to birth mother symptoms predicted lower child cortisol (main effect), as did postnatal exposure to adoptive parent symptoms (interaction effects). Adoptive mother 9-month symptoms exacerbated cortisol-lowering effects of both concurrent paternal symptoms and later (27-month) maternal symptoms, and the effect of birth mother cortisol. Lower child cortisol, in turn, was associated with higher child internalizing symptoms. Implications are discussed with respect to the intergenerational transmission of depression risk.

Genetic and environmental influences on individual differences in cortisol level and circadian rhythm in middle childhood

Individuals differ widely in cortisol output over the day, but the etiology of these individual differences remains poorly understood. Twin studies are useful for quantifying genetic and environmental influences on the variation in cortisol output, lending insight into underlying influences on the components of Hypothalamic-Pituitary-Adrenal (HPA) axis functioning. Salivary cortisol was assayed on 446 twin pairs (157 monozygotic, 289 dizygotic; ages 7-8). Parents helped youth collect saliva 30 min after waking, mid-afternoon, and 30 min prior to bedtime across 3 consecutive days. We used hierarchical linear modeling to extract predicted cortisol levels and to distinguish cortisol's diurnal rhythm using a slopes-as-outcome piecewise growth curve model; two slopes captured the morning-to-afternoon and afternoon-to-evening rhythm, respectively. Separate genetic models were then fit to cortisol level at waking, mid-afternoon, and evening as well as the diurnal rhythm across morning-to-afternoon and afternoon-to-evening hours. Three results from these analyses are striking. First, morning-to-afternoon cortisol level showed the highest additive genetic variance (heritability), consistent with prior research. Second, cortisol's diurnal rhythm had an additive genetic component, particularly across the morning-to-afternoon hours. In contrast, additive genetic variation did not significantly contribute to variation in afternoon-to-evening slope. Third, the majority of variance in cortisol concentration was associated with shared family environments. In summary, both genetic and environmental factors influence cortisol's circadian rhythm, and they do so differentially across the day.

Prenatal and postnatal maternal stress and wheeze in urban children: effect of maternal sensitization

RATIONALE

Critical periods for programming early wheeze risk may include pregnancy and infancy. Effects of timing remain poorly understood.

OBJECTIVES

Associations among prenatal and postnatal maternal stress and children's wheeze were prospectively examined in 653 families. Effect modification by maternal sensitization was also examined.

METHODS

Stress was indexed by a maternal negative life events (NLEs) score (range, 0-9) ascertained during pregnancy and between 1 and 2 years postpartum. Mothers reported child wheeze every 3 months up to age 2 years. Relationships of prenatal and postnatal maternal NLEs with repeated wheeze (≥2 episodes) were examined using logistic regression adjusting for covariates. Penalized splines were implemented to explore possible nonlinear associations. We also examined the interaction between prenatal stress and maternal sensitization indexed by allergen-specific IgE from maternal prenatal serum.

MEASUREMENTS AND MAIN RESULTS

Adjusted models considering prenatal or postnatal NLEs alone both showed an exposure-response relationship between higher stress and child wheeze. When considering prenatal and postnatal stress concurrently, only children of mothers with high stress in both periods were significantly more likely to wheeze (adjusted odds ratio, 3.04; 95% confidence interval, 1.67-5.53) than children of mothers reporting low stress in both periods. Associations between high prenatal stress and wheeze were significant in children born to nonsensitized mothers (any IgE <0.35 kU/L) but not in the sensitized group (P for interaction = 0.03).

CONCLUSIONS

Although children have heightened sensitivity to maternal stress in utero and in early childhood, those with higher stress in both periods were particularly at risk for wheeze. The prenatal maternal immune milieu modified effects.

Cortisol levels in response to starting school in children at increased risk for social phobia

BACKGROUND

Research on depression has identified hyperactivity of the HPA axis as a potential contributory factor to the intergenerational transmission of affective symptoms. This has not yet been examined in the context of social phobia. The current study compared HPA axis activity in response to a universal social stressor (starting school) in children of 2 groups of women: one with social phobia and one with no history of anxiety (comparison group). To determine specificity of effects of maternal social phobia, a third group of children were also examined whose mothers had generalised anxiety disorder (GAD).

METHOD

Children provided salivary cortisol samples in the morning, afternoon and at bedtime across 3 time-blocks surrounding the school start: a month before starting school (baseline), the first week at school (stress response), and the end of the first school term (stress recovery). Child behavioural inhibition at 14 months was assessed to explore the influence of early temperament on later stress responses.

RESULTS

All children displayed an elevation in morning and afternoon cortisol from baseline during the first week at school, which remained elevated until the end of the first term. Children in the social phobia group, however, also displayed an equivalent elevation in bedtime cortisol, which was not observed for comparison children or for children of mothers with GAD. Children in the social phobia group who were classified as 'inhibited' at 14 months displayed significantly higher afternoon cortisol levels overall.

SUMMARY

A persistent stress response to school in the morning and afternoon is typical for all children, but children of mothers with social phobia also display atypical elevations in evening cortisol levels when at school--signalling longer-term disruption of the circadian rhythm in HPA axis activity. This is the first study to report HPA axis disruption in children at increased risk of developing social phobia. Future research should determine whether this represents a pathway for symptom development, taking early temperament into account.

Child maltreatment increases sensitivity to adverse social contexts: neighborhood physical disorder and incident binge drinking in Detroit

INTRODUCTION

Exposure to child maltreatment is associated with elevated risk for behavioral disorders in adulthood. One explanation for this life-course association is that child maltreatment increases vulnerability to the effects of subsequent stressors; however, the extent to which maltreatment increases sensitivity to social context has never been examined. We evaluated whether the association between neighborhood physical disorder and binge drinking was modified by child maltreatment exposure.

METHODS

Data were drawn from the Detroit Neighborhood Health Study, a prospective representative sample of predominately African Americans in the Detroit population. Neighborhood physical disorder was measured via systematic neighborhood assessment. Child maltreatment indicators included self-reported physical, sexual, and emotional abuse. Incident binge drinking was defined as at least one episode of ≥5 drinks (men) or ≥4 drinks (women) in the past 30-day period among those with no binge drinking at baseline (N=1013).

RESULTS

Child maltreatment and neighborhood physical disorder interacted to predict incident binge drinking (B=0.16, p=0.02) and maximum number of past 30-day drinks (B=0.15, p=0.04), such that neighborhood physical disorder predicted problematic alcohol use only among individuals with high exposure to child maltreatment.

CONCLUSION

The results add to the growing literature that African Americans in the US are exposed to an array of stressors that have pernicious consequences for problematic alcohol use. Our results document the need for increased attention to the potential for at-risk alcohol use among populations with a high degree of stress exposure.

The diurnal salivary cortisol pattern of adolescents from families with single, ill and healthy parents

OBJECTIVE

Adolescents of single and/or chronically ill parents (target groups) reportedly have elevated psychological stress. However, their salivary cortisol pattern as part of the physiological stress system has not been compared to controls. The aim of this study is to examine differential outcomes in the diurnal cortisol pattern of the target groups.

METHODS

In total, 100 adolescents of three groups with either single, chronically ill or two healthy parents were compared on cortisol. Three salivary cortisol samples were taken after awakening, one sample at noon and one sample at 20:00 p.m. during a non-school day. Group differences and interaction effects between measurement (5 times), group membership and covariates were tested through linear mixed modeling, repeated measures. Covariates were children's sex and age, socioeconomic status (SES) and parental depression as measured with the Beck Depression Inventory.

RESULTS

The three groups did not differ significantly concerning the amount of salivary cortisol, even after controlling for the covariates. The target groups had a lower SES than adolescents with two healthy parents. In addition, chronically ill parents were more depressed than single and healthy parents. Male sex and older age of the child, and lower parental depression were associated with increased cortisol values throughout the day.

CONCLUSION

Research on cortisol in children should control for children's sex and age, and parental depression. Adolescents with single and/or chronically ill parents displayed a healthy pattern of diurnal salivary cortisol.

Stress, cortisol and well-being of caregivers and children in home-based child care: a case for differential susceptibility

BACKGROUND

We examined whether children cared for by stressed caregivers show lower socio-emotional well-being and more stress, compared with children cared for by less stressed caregivers.

METHODS

Perceived stress and cortisol levels of professional caregivers (n = 44), and associations with children's (n = 44) well-being and cortisol levels in home-based child care were examined.

RESULTS

Caregiver perceived stress and cortisol levels were related to children's well-being but not to children's cortisol levels. Children's social fearfulness acted as a moderator between caregivers' mean ratio of diurnal change in cortisol and children's well-being. When caregiver cortisol levels decreased, more fearful children were reported higher on well-being than less fearful peers. In contrast, when caregiver cortisol levels increased, more fearful children were reported lower on well-being.

CONCLUSIONS

The findings point to differential susceptibility. Child care organizations and parents need to notice that a non-stressful child care environment is in particular important for children with a difficult temperament.

Kindergarten stressors and cumulative adrenocortical activation: the "first straws" of allostatic load?

Using an ethnically diverse longitudinal sample of 338 kindergarten children, this study examined the effects of cumulative contextual stressors on children's developing hypothalamic-pituitary-adrenocortical (HPA) axis regulation as an early life indicator of allostatic load. Chronic HPA axis regulation was assessed using cumulative, multiday measures of cortisol in both the fall and spring seasons of the kindergarten year. Hierarchical linear regression analyses revealed that contextual stressors related to ethnic minority status, socioeconomic status, and family adversity each uniquely predicted children's daily HPA activity and that some of those associations were curvilinear in conformation. Results showed that the quadratic, U-shaped influences of family socioeconomic status and family adversity operate in different directions to predict children's HPA axis regulation. Results further suggested that these associations differ for White and ethnic minority children. In total, this study revealed that early childhood experiences contribute to shifts in one of the principal neurobiological systems thought to generate allostatic load, confirming the importance of early prevention and intervention efforts. Moreover, findings suggested that analyses of allostatic load and developmental theories accounting for its accrual would benefit from an inclusion of curvilinear associations in tested predictive models.