No association between hair cortisol or cortisone and brain morphology in children

Prenatal family income, but not parental education, is associated with resting brain activity in 1-month-old infants

Childhood socioeconomic disadvantage is associated with disparities in development and health, possibly through adaptations in children's brain function. However, it is not clear how early in development such neural adaptations might emerge. This study examined whether prenatal family socioeconomic status, operationalized as family income and average years of parental education, prospectively predicts individual differences in infant resting electroencephalography (EEG; theta, alpha, beta, and gamma power) at approximately 1 month of age (N = 160). Infants of mothers reporting lower family income showed more lower-frequency (theta) and less higher-frequency (beta and gamma) power. These associations held when adjusting for other prenatal and postnatal experiences, as well as infant demographic and health-related factors. In contrast, parental education was not significantly associated with infant EEG power in any frequency band. These data suggest that lower prenatal family income is associated with developmental differences in brain function that are detectable within the first month of life.

Socioeconomic Disparities in Hypothalamic-Pituitary-Adrenal Axis Regulation and Prefrontal Cortical Structure

Socioeconomic disadvantage during childhood predicts an increased risk for mental health problems across the life span. Socioeconomic disadvantage shapes multiple aspects of children's proximal environments and increases exposure to chronic stressors. Drawing from multiple literatures, we propose that childhood socioeconomic disadvantage may lead to adaptive changes in the regulation of stress response systems including the hypothalamic-pituitary-adrenal (HPA) axis. These changes, in turn, affect the development of prefrontal cortical (PFC) circuitry responsible for top-down control over cognitive and emotional processes. Translational findings indicate that chronic stress reduces dendritic complexity and spine density in the medial PFC and anterior cingulate cortex, in part through altered HPA axis regulation. Socioeconomic disadvantage has frequently been associated with reduced gray matter in the dorsolateral and ventrolateral PFC and anterior cingulate cortex and lower fractional anisotropy in the superior longitudinal fasciculus, cingulum bundle, and uncinate fasciculus during middle childhood and adolescence. Evidence of socioeconomic disparities in hair cortisol concentrations in children has accumulated, although null findings have been reported. Coupled with links between cortisol levels and reduced gray matter in the PFC and anterior cingulate cortex, these results support mechanistic roles for the HPA axis and these PFC circuits. Future longitudinal studies should simultaneously consider multiple dimensions of proximal factors, including cognitive stimulation, while focusing on epigenetic processes and genetic moderators to elucidate how socioeconomic context may influence the HPA axis and PFC circuitry involved in cognitive and emotional control. These findings, which point to modifiable factors, can be harnessed to inform policy and more effective prevention strategies.

Associations between cortisol stress responses and limbic volume and thickness in young adults: An exploratory study

The investigation of the relationship between neural measures of limbic structures and hypothalamic pituitary adrenal axis responses to acute stress exposure in healthy young adults has so far focused in particular on task-based and resting state functional connectivity studies. Thus, the present study examined the association between limbic volume and thickness measures and acute cortisol responses to the psychosocial stress paradigm ScanSTRESS. Using Permutation Analysis of Linear Models controlling for sex, age and total brain volume, the associations between (sex-specific) cortisol increases and human connectome project style anatomical variables of limbic structures (i.e. volume and thickness) were investigated in 66 healthy and young (18-33 years) subjects (35 men, 31 women taking oral contraceptives). In addition, exploratory (sex-specific) bivariate correlations between cortisol increases and structural measures were conducted. The present data provide interesting new insights into the involvement of striato-limbic structures in psychosocial stress processing, suggesting that acute cortisol stress responses are also associated with mere structural measures of the human brain. Thus, our preliminary findings suggest that not only situation- and context-dependent reactions of the limbic system (i.e. blood oxygenation level-dependent reactions) are related to acute (sex-specific) cortisol stress responses but also basal and somewhat more constant structural measures. Our study hereby paves the way for further analyses in this context and highlights the relevance of the topic.

Associations of prenatal maternal depressive symptoms with cord blood glucocorticoids and child hair cortisol levels in the project viva and the generation R cohorts: a prospective cohort study

BACKGROUND

Prior studies have reported conflicting results regarding the association of prenatal maternal depression with offspring cortisol levels. We examined associations of high levels of prenatal depressive symptoms with child cortisol biomarkers.

METHODS

In Project Viva (n = 925, Massachusetts USA), mothers reported their depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, cord blood glucocorticoids were measured at delivery, and child hair cortisol levels were measured in mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In the Generation R Study (n = 1644, Rotterdam, The Netherlands), mothers reported depressive symptoms using the Brief Symptom Inventory (BSI) during pregnancy, and child hair cortisol was measured at a mean (SD) age of 6.0 (0.5) years. We used cutoffs of ≥ 13 for the EPDS and > 0.75 for the BSI to indicate high levels of prenatal depressive symptoms. We used multivariable linear regression models adjusted for child sex and age (at outcome), and maternal pre-pregnancy BMI, education, social support from friends/family, pregnancy smoking status, marital status, and household income to assess associations separately in each cohort. We also meta-analyzed childhood hair cortisol results from both cohorts.

RESULTS

8.0% and 5.1% of women respectively experienced high levels of prenatal depressive symptoms in Project Viva and the Generation R Study. We found no associations between high levels of maternal depressive symptoms during pregnancy and child cortisol biomarkers in either cohort.

CONCLUSIONS

The present study does not find support for the direct link between high levels of maternal depressive symptoms and offspring cortisol levels.

Socioeconomic factors, stress, hair cortisol, and white matter microstructure in children

Socioeconomic disadvantage has been linked to increased stress exposure in children and adults. Exposure to stress in childhood has been associated with deleterious effects on cognitive development and well-being throughout the lifespan. Further, exposure to stress has been associated with differences in brain development in children, both in cortical and subcortical gray matter. However, less is known about the associations among socioeconomic disadvantage, stress, and children's white matter development. In this study, we investigated whether socioeconomic disparities would be associated with differences in white matter microstructure in the cingulum bundle, as has been previously reported. We additionally investigated whether any such differences could be explained by differences in stress exposure and/or physiological stress levels. White matter tracts were measured via diffusion tensor imaging in 58 children aged 5-9 years. Results indicated that greater exposure to stressful life events was associated with higher child hair cortisol concentrations. Further, physiological stress, as indexed by hair cortisol concentrations, were associated with higher fractional anisotropy in the cingulum bundle. These results have implications for better understanding how perceived and physiological stress may alter neural development during childhood.

Growth trajectories of the human fetal brain in healthy and complicated pregnancies and associations with neurodevelopmental outcome in the early life course

BACKGROUND

There is a need for non-invasive prenatal markers of the brain to assess fetuses at risk for poor postnatal neurodevelopmental outcome. Periconceptional maternal conditions and pregnancy complications impact prenatal brain development.

AIMS

To investigate associations between growth trajectories of fetal brain structures and neurodevelopmental outcome in children in the early life course.

STUDY DESIGN

Periconceptional prospective observational cohort.

SUBJECTS

Singleton pregnancies were included in the Rotterdam periconception cohort. Two- and three-dimensional ultrasound scans at 22, 26 and 32 weeks gestational age were analysed.

OUTCOME MEASURES

Head circumference (HC), cerebellum, corpus callosum (CC), Sylvian fissure, insula and parieto-occipital fissure (POF) were measured. Neurodevelopment was evaluated using the Age-and-Stages-questionnaire-3 (ASQ-3) and the Child-Behaviour-Checklist (CBCL) at 2 years of age. Linear mixed models, used to estimate the prenatal brain growth trajectories, and linear regression models, used to evaluate the associations between prenatal brain structures and neurodevelopmental outcomes, were applied in the total study population, and in subgroups: fetal growth restriction (FGR), preterm birth (PTB), fetal congenital heart disease (CHD), and uncomplicated controls.

RESULTS

Consent for participation was received from parents on behalf of their child 138/203 (68%). ASQ-3 was completed in 128/203 children (63%) and CBCL in 93/203 children (46%). Significant smaller subject-specific growth trajectories (growth rate of CC, HC, left insula, left POF and right POF and the baseline size of CC, HC, left POF and right POF) were found in the FGR subgroup, compared to the other subgroups (all p-values <0.05). In the total group (n = 138), the growth rate of the left insula was associated with poorer ASQ-3 score (β = -869.51; p < 0.05). Healthy controls (n = 106) showed a comparable association (β = -1209.87; p < 0.01). FGR (n = 10) showed a larger baseline size of the right Sylvian fissure in association with poorer CBCL-score (β = 4.13; p < 0.01). In CHD (n = 12) the baseline size of the left Sylvian fissure and its growth rate were associated with respectively poorer and better CBCL-scores (β = 3.11; p < 0.01); (β = -171.99; p < 0.01). In PTB (n = 10) no associations were found.

CONCLUSIONS

This explorative study suggests associations between ultrasound measurements of fetal brain growth and neurodevelopmental outcome at 2 years of age. In future, this non-invasive technique may improve early identification of fetuses at risk for neurodevelopmental outcome and follow-up postnatal clinical care.

Lack of FKBP51 Shapes Brain Structure and Connectivity in Male Mice

BACKGROUND

Stress exposure as well as psychiatric disorders are often associated with abnormalities in brain structure or connectivity. The co-chaperone FK506-binding protein 51 (FKBP51) is a regulator of the stress system and is associated with a risk to develop stress-related mental illnesses.

PURPOSE

To assess the effect of a general FKBP51 knockout on brain structure and connectivity in male mice.

STUDY TYPE

Animal study.

ANIMAL MODEL

Two cohorts of FKBP51 knockout (51KO) and wildtype (WT) mice. The first cohort was comprised of n = 18 WT and n = 17 51KOs; second cohort n = 10 WT and n = 9 51KOs.

FIELD STRENGTH/SEQUENCE

9.4T/3D gradient echo (VBM), DTI-EPI (DTI).

ASSESSMENT

Voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). For VBM, all procedures were executed in SPM12. DTI: FMRIB Software Library (FSL) Tract Based Statistics (TBSS) were integrated within DTI-TK, allowing the creation of a mean FA skeleton. A voxelwise statistical analysis was applied between WT and 51KO mice.

STATISTICAL TEST

Volumetric differences were collected at a threshold of P < 0.005, and only clusters surviving a familywise error correction on the cluster level (pFWE, cluster <0.05) were further considered. VBM data were analyzed using a two-sample t-test. The Threshold Free Cluster Enhancement (TFCE) method was used to derive uncorrected-P statistical results at a P-level of 0.01.

RESULTS

The structural analysis revealed two clusters of significantly larger volumes in the hypothalamus, periaqueductal gray, and dorsal raphe region of WT animals. DTI measurements, however, demonstrated statistically higher fractional anisotropy (FA) values for 51KO animals in locations including the anterior commissure, fornix, and posterior commissure/superior colliculus commissure region.

DATA CONCLUSION

This study used in vivo structural MRI and DTI to demonstrate that a lack of FKBP51 leads to alterations in brain architecture and connectivity in male mice. These findings are of particular translational relevance for our understanding of the neuroanatomy underlying the interaction of FKBP5 genetic status, stress susceptibility, and psychiatric disorders.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 1.

Socioeconomic Disparities in Chronic Physiologic Stress Are Associated With Brain Structure in Children

BACKGROUND

Socioeconomic factors have been consistently linked with the structure of children's hippocampus and anterior cingulate cortex (ACC). Chronic stress-as indexed by hair cortisol concentration-may represent an important mechanism underlying these associations. Here, we examined associations between hair cortisol and children's hippocampal and ACC structure, including across hippocampal subfields, and whether hair cortisol mediated associations between socioeconomic background (family income-to-needs ratio, parental education) and the structure of these brain regions.

METHODS

Participants were 5- to 9-year-old children (N = 94; 61% female) from socioeconomically diverse families. Parents and children provided hair samples that were assayed for cortisol. High-resolution, T1-weighted magnetic resonance imaging scans were acquired, and FreeSurfer 6.0 was used to compute hippocampal volume and rostral and caudal ACC thickness and surface area (n = 37 with both child hair cortisol and magnetic resonance imaging data; n = 41 with both parent hair cortisol and magnetic resonance imaging data).

RESULTS

Higher hair cortisol concentration was significantly associated with smaller CA3 and dentate gyrus hippocampal subfield volumes but not with CA1 or subiculum volume. Higher hair cortisol was also associated with greater caudal ACC thickness. Hair cortisol significantly mediated associations between parental education level and CA3 and dentate gyrus volumes; lower parental education level was associated with higher hair cortisol, which in turn was associated with smaller volume in these subfields.

CONCLUSIONS

These findings point to chronic physiologic stress as a potential mechanism through which lower parental education level leads to reduced hippocampal volume. Hair cortisol concentration may be an informative biomarker leading to more effective prevention and intervention strategies aimed at childhood socioeconomic disadvantage.

Neurobiological mechanisms underlying sex-related differences in stress-related disorders: Effects of neuroactive steroids on the hippocampus

Men and women differ in their vulnerability to a variety of stress-related illnesses, but the underlying neurobiological mechanisms are not well understood. This is likely due to a comparative dearth of neurobiological studies that assess male and female rodents at the same time, while human neuroimaging studies often don't model sex as a variable of interest. These sex differences are often attributed to the actions of sex hormones, i.e. estrogens, progestogens and androgens. In this review, we summarize the results on sex hormone actions in the hippocampus and seek to bridge the gap between animal models and findings in humans. However, while effects of sex hormones on the hippocampus are largely consistent in animals and humans, methodological differences challenge the comparability of animal and human studies on stress effects. We summarise our current understanding of the neurobiological mechanisms that underlie sex-related differences in behavior and discuss implications for stress-related illnesses.

rs1360780 of the FKBP5 gene modulates the association between maternal acceptance and regional gray matter volume in the thalamus in children and adolescents

Investigating the effects of gene–environment interactions (G × E) with regard to brain structure may help to elucidate the putative mechanisms associated with psychiatric risk. rs1360780 (C/T) is a functional single-nucleotide polymorphism (SNP) in the gene encoding FK506–binding protein 5 (FKBP5), which is involved in the regulation of the hypothalamic–pituitary–adrenal (HPA) axis stress responses. The minor (T) allele of FKBP5 is considered a risk allele for stress-related disorders, due to the overproduction of FKBP5, which results in impaired communication of stress signals with the HPA axis. Previous studies have reported that interactions between childhood maltreatment and the rs1360780 genotype affect structures in subcortical areas of the brain. However, it is unclear how this SNP modulates the association between non-adverse environments and brain structure. In this study, we examined the interactive effect of the rs1360780 genotype and maternal acceptance on the regional gray matter volume (rGMV) in 202 Japanese children. Maternal acceptance was assessed using a Japanese psychological questionnaire for mothers. Whole-brain multiple regression analysis using voxel-based morphometry showed a significant positive association between maternal acceptance and rGMV in the left thalamus of T-allele carriers, while a significant negative association was found in C/C homozygotes. Post-hoc analysis revealed that at or below the 70th percentiles of maternal acceptance, the T-allele carriers had a reduced thalamic rGMV compared with that of C/C homozygotes. Thus, our investigation indicated that the effect of the maternal acceptance level on brain development was different, depending on the rs1360780 genotype. Importantly, we found that the differences in brain structure between the T-allele carriers and C/C homozygotes at low to moderate levels of maternal acceptance, which is not equivalent to maltreatment. The present study contributes to the G × E research by highlighting the necessity to investigate the role of non-adverse environmental factors.

The association of potential stressors with hair steroids in parents with small children: The Ulm SPATZ health study

Previous studies have reported weak associations between questionnaire-based stress measurements and hair steroids. A stronger relationship may exist in highly stressed subpopulations or with stress brought up by novel or unpredictable situations. In the Ulm SPATZ Health Study, conducted in Ulm, Germany, baseline recruitment 04/2012 to 05/2013, we analyzed data of families enrolled shortly after childbirth. Mothers completed standardized questionnaires assessing sociodemographic, health- and family-life-related factors, and the Screening Scale of the Trier Inventory of Chronic Stress (TICS) at 6 months (T2) and 12 months postpartum (T3). Their current partners completed SSCS-TICS and an Effort-Reward Imbalance (ERI) Questionnaire obtained at 6 weeks postpartum (T1). Partners (n = 375 at T1) and mothers (n = 654 at T2 or T3) provided a 2 to 3-cm hair segment for hair analysis. Adjusted linear and cubic spline regressions were used to analyze (non-)linear relationships between potential stressors and hair cortisol (hairF) and hair cortisone (hairE) concentrations as well as the respective change scores between 12 months and 6 months. Lacking social recognition and high paternal work overload were significantly associated with paternal hairF in cubic spline models (test for overall association, chi² = 8.24, p = 0.041, chi² = 8.41, p = 0.038) but not in linear models. However, the association between ERI and hairF (chi² = 7.54, p = 0.059) was marginally significant. Maternal education was related to maternal hairF and hairE at T2. No association was observed between maternal postpartum employment and hair steroids at T2 or T3. Conversely, we could show a relationship between some change scores of stress and hairE in mothers. Considering non-linearity and family-related stressors, there are few associations between questionnaire-based stress measurements and hairF or hairE. Novelty of stressors was not shown to be a relevant factor.

Interaction of schizophrenia polygenic risk and cortisol level on pre-adolescent brain structure

The etiology of schizophrenia is multi-factorial with early neurodevelopmental antecedents, likely to result from a complex interaction of genetic and environmental risk. However, few studies have examined how schizophrenia polygenic risk scores (PRS) are moderated by environmental factors in shaping neurodevelopmental brain structure, prior to the onset of psychotic symptoms. Here, we examined whether hair cortisol, a quantitative metric of chronic stress, moderated the association between genetic risk for schizophrenia and pre-adolescent brain structure. This study was embedded within the Generation R Study, involving pre-adolescents of European ancestry assessed regarding schizophrenia PRS, hair cortisol, and brain imaging (n = 498 structural; n = 526 diffusion tensor imaging). Linear regression was performed to determine the association between schizophrenia PRS, hair cortisol level, and brain imaging outcomes. Although no single measure exceeded the multiple testing threshold, nominally significant interactions were observed for total ventricle volume (P_interaction = 0.02) and global white matter microstructure (P_interaction = 0.01) - two of the most well replicated brain structural findings in schizophrenia. These findings provide suggestive evidence for the joint effects of schizophrenia liability and cortisol levels on brain correlates in the pediatric general population. Given the widely replicated finding of ventricular enlargement and lower white matter integrity among schizophrenia patients, our findings generate novel hypotheses for future research on gene-environment interactions affecting the neurodevelopmental pathophysiology of schizophrenia.

Correlates of hair cortisol concentrations in disadvantaged young children

Children from highly disadvantaged families tend to experience worse health, educational, and job outcomes than less disadvantaged peers. However, the mechanisms underlying these relationships remain to be explicated. In particular, few studies have investigated the relationships between the psychosocial influences that children are exposed to early in life and longer term cortisol output. This study aims to contribute to the literature by exploring how disadvantaged young children's experiences of family adversity, and parenting and family functioning, are related to their long-term cortisol levels. A sample of 60 children (26 males, mean = 4.25 years, SD = 1.68) and their mothers (mean = 34.18 years, SD = 7.11) from a low-income population took part in a single assessment. Mothers completed questionnaires on the family environment, parenting practices, and child behaviour. Children provided a hair sample for cortisol assay and anthropometric measures. A parsimonious multivariate regression model (including potential predictors identified by a selection algorithm) was used to investigate the correlates of hair cortisol concentration (HCC) in children. Higher levels of social exclusion, being male, and younger age were each associated with higher HCC. Maternal nurturing and emotion coaching were associated with lower HCC. Findings suggest that chronic stress may underlie relationships between adversity and its long-term effects and that HCC offers a promising method for examining chronic stress in children and evaluating interventions by which it can be ameliorated.