Hair cortisol concentration in mothers and their children: roles of maternal sensitivity and child symptoms of attention-deficit/hyperactivity disorder

Stability and inter-family associations of hair endocannabinoid and N-acylethanolamines across the perinatal period in mothers, fathers, and children

Analysis of endocannabinoids (ECs) and N-acylethanolamines (NAEs) in hair is assumed to retrospectively assess long-term EC/NAE concentrations. To inform their use, this study investigated stability of EC/NAE hair concentrations in mothers, fathers, and their children across the perinatal period as well as associations between family members. In a prospective cohort study, EC (AEA, 1-AG/2-AG) and NAE (SEA, PEA, OEA) levels were quantified in hair samples taken four times in mothers (n = 336) and their partners (n = 225) from pregnancy to two years postpartum and in offspring (n = 319) from shortly after birth to two years postpartum. Across the perinatal period, maternal and paternal hair ECs/NAEs showed poor multiple-test consistency (16-36%) and variable relative stability, as well as inconsistent absolute stability for mothers. Regarding children, hair ECs/NAEs evidenced poor multiple-test consistency (4-19%), no absolute stability, and either no or variable relative stability. Hair ECs/NAEs showed small to medium significant associations across the perinatal period within couples and parent-child dyads. Findings suggest hair ECs/NAEs during the perinatal period possess variable stability in adults, albeit more stability in fathers than mothers in this time. This highlights the need to further investigate factors associated with changes in hair ECs/NAEs across time. The first two years of life may be a dynamic phase for the endocannabinoid system in children, potentially characterized by complex within-family correspondence that requires further systematic investigation.

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.

Continuity of psychopathology v. resilience across the transition to adolescence: role of hair cortisol and sensitive caregiving

BACKGROUND

The transition to adolescence implicates heightened vulnerability alongside increased opportunities for resilience. Contexts of early life stress (ELS) exacerbate risk; still, little research addressed biobehavioral mediators of risk and resilience across the adolescent transition following ELS. Utilizing a unique cohort, we tested biosocial moderators of chronicity in adolescents' internalizing disorders v. resilience.

METHOD

Families exposed to chronic war-related trauma, v. controls, were followed. We utilized data from three time-points framing the adolescent transition: late childhood (N = 177, Mage = 9.3 years ± 1.41), early adolescence (N = 111, Mage = 11 0.66 years ± 1.23), and late adolescence (N = 138, Mage = 15.65 years ± 1.31). In late childhood and late adolescence children's internalizing disorders were diagnosed. At early adolescence maternal and child's hair cortisol concentrations (HCC), maternal sensitivity, and mothers' post-traumatic symptoms evaluated.

RESULTS

War-exposed children exhibited more internalizing disorders of chronic trajectory and mothers were less sensitive and more symptomatic. Three pathways elucidated the continuity of psychopathology: (a) maternal sensitivity moderated the risk of chronic psychopathology, (b) maternal post-traumatic symptoms mediated continuity of risk, (c) trauma exposure moderated the association between child internalizing disorders at late childhood and maternal HCC, which linked with child HCC. Child HCC linked with maternal post-traumatic symptoms, which were associated with child disorders in late adolescence.

CONCLUSION

Results demonstrate the complex interplay of maternal and child's biosocial factors as mediators and moderators of risk chronicity across the adolescent transition following trauma. Findings are first to utilize maternal and child's HCC as biomarkers of chronic stress v. resilience during adolescence, a period of neural reorganization and personal growth that shapes the individual's lifetime adaptation.

Household Social Needs, Emotional Functioning, and Stress in Low-Income Latinx Children and their Mothers

Latinx families may be particularly vulnerable to emotional dysfunction, due to higher rates of economic hardship and complex social influences in this population. Little is known about the impact of environmental stressors such as unmet social needs and maternal stress on the emotional health of Latinx children from low-income families. We conducted secondary analyses using survey and biomarker data from 432 Latinx children and mothers collected in a separate study. We used binomial and multinomial logistic regression to test if household social needs, or maternal perceived stress or hair cortisol concentration (HCC), predicted child measures of emotional functioning or child HCC, independent of relevant sociodemographic factors. Approximately 40% of children in the sample had symptoms consistent with emotional dysfunction, and over 37% of households reported five or more social needs. High perceived maternal stress predicted higher odds of child emotional dysfunction (OR = 2.15; 95% CI [1.14, 4.04]; p = 0.01), and high maternal HCC was positively associated with high child HCC (OR = 10.60; 95% CI [4.20, 26.74]; p < 0.01). Most individual household social needs, as well as the level of household social need, were not independently associated with child emotional dysfunction or child HCC. Our findings begin to define a framework for understanding emotional health, stress, and resilience when caring for Latinx children and mothers living with high levels of social need, and the need for integrated mental health and social needs screening and interventions in settings that serve this population.

Unmet Social Needs and Patterns of Hair Cortisol Concentration in Mother-Child Dyads

Background

Mothers and their children demonstrate dyadic synchrony of hypothalamic-pituitary-adrenal (HPA) axis function, likely influenced by shared genetic or environmental factors. Although evidence has shown that chronic stress exposure has physiologic consequences for individuals-including on the HPA axis-minimal research has explored how unmet social needs such as food and housing instability may be associated with chronic stress and HPA axis synchrony in mother-child dyads.

Methods

We conducted a secondary analysis of data from 364 mother-child dyads with low-income recruited during a randomized trial conducted in an urban pediatric clinic. We used latent profile analysis (LPA) to identify subgroups based on naturally occurring patterns of within-dyad hair cortisol concentration (HCC). A logistic regression model predicted dyadic HCC profile membership as a function of summative count of survey-reported unmet social needs, controlling for demographic and health covariates.

Results

LPA of HCC data from dyads revealed a 2-profile model as the best fit. Comparisons of log HCC for mothers and children in each profile group resulted in significantly "higher dyadic HCC" versus "lower dyadic HCC" profiles (median log HCC for mothers: 4.64 vs 1.58; children: 5.92 vs 2.79, respectively; P < .001). In the fully adjusted model, each one-unit increase in number of unmet social needs predicted significantly higher odds of membership in the higher dyadic HCC profile when compared to the lower dyadic HCC profile (odds ratio  =  1.13; 95% confidence interval [1.04-1.23]; P  =  .01).

Conclusion

Mother-child dyads experience synchronous patterns of physiologic stress, and an increasing number of unmet social needs is associated with a profile of higher dyadic HCC. Interventions aimed at decreasing family-level unmet social needs or maternal stress are, therefore, likely to affect pediatric stress and related health inequities; efforts to address pediatric stress similarly may affect maternal stress and related health inequities. Future research should explore the measures and methods needed to understand the impact of unmet social needs and stress on family dyads.

Cortisol Reactivity and Observed Parenting among Mothers of Children with and without ADHD

OBJECTIVE

Neurobiological models suggest links between maternal cortisol reactivity and parenting; however, no studies have examined cortisol reactivity and parenting in mothers of school-age children with ADHD.

METHOD

We examined the relationship between observed parenting and maternal cortisol reactivity in two laboratory contexts: the Trier Social Stress Task (TSST) and parenting-child interaction (PCI). Mothers of children with (N = 24) and without (N = 36) ADHD participated.

RESULTS

During the TSST, greater cortisol output and increase were associated with decreased positive and increased negative parenting. However, during the PCI, cortisol output was associated with increased self-reported and observed positive parenting, and decreased observed negative parenting. Cortisol change during the PCI was associated with decreased observed positive parenting and increased self-reported negative parenting. Among mothers of children with ADHD, cortisol output during the PCI was negatively associated with negative, inconsistent parenting. Change in cortisol predicted more inconsistent discipline and corporal punishment.

CONCLUSION

Findings contribute to an integrative biological, psychological, and cognitive process model of parenting in families of children with ADHD.

Lower Maternal Chronic Physiological Stress and Better Child Behavior at 18 Months: Follow-Up of a Cluster Randomized Trial of Neonatal Intensive Care Unit Family Integrated Care

OBJECTIVE

To assess whether Family Integrated Care (FICare) in the neonatal intensive care unit improves maternal chronic physiological stress and child behavior at 18 months of corrected age for infants born preterm.

STUDY DESIGN

Follow-up of a multicenter, prospective cluster-randomized controlled trial comparing FICare and standard care of children born at <33 weeks of gestation and parents, stratified by tertiary neonatal intensive care units, across Canada. Primary outcomes at 18 months of corrected age were maternal stress hormones (cortisol, ie, hair cumulative cortisol [HCC], dehydroepiandrosterone [DHEA]) assayed from hair samples. Secondary outcomes included maternal reports of parenting stress, child behaviors (Internalizing, Externalizing, Dysregulation), and observer-rated caregiving behaviors. Outcomes were analyzed using multilevel modeling.

RESULTS

We included 126 mother-child dyads from 12 sites (6 FICare sites, n = 83; 6 standard care sites, n = 43). FICare intervention significantly lowered maternal physiological stress as indicated by HCC (B = -0.22 [-0.41, -0.04]) and cortisol/DHEA ratio (B = -0.25 [-0.48, -0.02]), but not DHEA (B = 0.01 [-0.11, 0.14]). Enrollment in FICare led to lower child Internalizing (B = -0.93 [-2.33, 0.02]) and Externalizing behavior T scores (B = -0.91 [-2.25, -0.01]) via improvements to maternal HCC (mediation). FICare buffered the negative effects of high maternal HCC on child Dysregulation T scores (B = -11.40 [-23.01, 0.21]; moderation). For mothers reporting high parenting stress at 18 months, FICare was related to lower Dysregulation T scores via maternal HCC; moderated mediation = -0.17 (-0.41, -0.01).

CONCLUSIONS

FICare has long-term beneficial effects for mother and child, attenuating maternal chronic physiological stress, and improving child behavior in toddlerhood.

CLINICAL TRIAL REGISTRATION

NCT01852695.

Sociodemographics and chronic stress in mother-toddler dyads living in poverty

Experiencing chronic stress early in life is associated with later health disparities, and poverty may be a significant stressor for both mothers and children. With a sample of primarily Black and White mothers (N = 75) and toddlers (N = 71) living in poverty in the United States, we examined the direct relations between sociodemographic conditions of poverty and chronic physiological stress. Mothers completed questionnaires on sociodemographics, including mother/toddler race, mother's education, father's education, poverty level, economic hardship, marital status, unemployment status, and toddler sex. Physiological chronic stress was measured by assaying the cortisol content of 4 cm samples of hair cut from the posterior vertex of mothers and toddlers (20-24 months of age) to represent 4 months of stress. Mothers' and toddlers' chronic stress was significantly, moderately, and positively associated. Toddlers had a trending relationship of moderately higher chronic stress if they were Black compared to not Black. Mothers had significantly, moderately higher chronic stress if they were Black or had a Black toddler (compared to not Black), not married (compared to married), or were working (compared to not working). The findings suggest that these mothers, simultaneously navigating poverty and parenting a toddler, need resources to reduce chronic stress.

The impact of preschool child and maternal attention-deficit/hyperactivity disorder (ADHD) symptoms on mothers' perceived chronic stress and hair cortisol

Providing care for a child with attention-deficit/hyperactivity disorder (ADHD) is associated with parenting stress. Moreover, adults with elevated ADHD symptoms report increased perceived stress. Despite this, it has rarely been examined whether and how child and maternal ADHD symptoms may affect maternal perceived stress and the stress-sensitive hypothalamic–pituitary–adrenal axis. This study therefore investigated the possible impact of child and maternal ADHD symptoms on mothers' perceived chronic stress and hair cortisol concentration (HCC), while simultaneously considering the effects of child oppositional defiant/conduct disorder (ODD/CD) and maternal depressive symptomatology. In total, 124 mothers (35.96 ± 5.21 years) of preschool children were included. Maternal perceived stress, ADHD and depressive symptoms were assessed using self-report measures. Child ADHD symptoms were assessed using an interview and questionnaires completed by mothers and teachers. Additionally, mothers provided information about their children’s ODD/CD symptoms. Hair samples were taken from mothers to assess HCC. Child and maternal ADHD, child ODD/CD, and maternal depressive symptoms accounted for 50% of the variance in perceived chronic stress (F(4, 119) = 30.24; p < 0.01), with only maternal ADHD (β = 0.52, p < 0.01) and depressive symptoms (β = 0.49, p < 0.01) being uniquely significant. Maternal ADHD symptoms did not moderate the relationship between child ADHD symptoms and maternal perceived chronic stress (b = − 0.01; SE b = 0.17; t(5, 118) = − 0.05; p = 0.96). Mother’s age became the only significant predictor of maternal HCC (β = 0.29; p < 0.01). Based on these findings, practitioners are advised to be aware of and take into account possible maternal ADHD and depressive symptomatology and perceived chronic stress when treating children diagnosed with ADHD.

Hair sampling for cortisol analysis with mother-toddler dyads living in low-income homes

BACKGROUND

A first step to advance stress science research in young children is understanding the relationship between chronic stress in a mother and chronic stress in her child. One non-invasive measure of chronic stress is hair cortisol. However, little is known about strategies for hair sampling in mother-toddler dyads living in low-income homes in the U.S. To address prior limitations, the purpose of this study was to understand the feasibility of sampling hair for cortisol analysis in mother-toddler dyads living in low-income homes in the U.S. We examined feasibility related to participation, eligibility, and gathering an adequate hair sample weight.

METHODS

We approached 142 low-income, racially diverse, urban-dwelling mothers who were participating in an ongoing longitudinal birth cohort study for informed consent to cut approximately 150 hairs from the posterior vertex of their scalp and their toddlers' (20-24 months) scalp. We demonstrated the process of sampling hair with a hairstyling doll during home visits to the mother and toddler using rounded-end thinning shears.

RESULTS

Overall, 94 of 142 mother-toddler dyads (66 %) participated in hair sampling. The most common reason for participation refusal was related to hairstyle. All but three hair samples were of adequate weight for cortisol extraction.

DISCUSSION

The findings from this study can help researchers address sampling feasibility concerns in hair for cortisol analysis research in mother-toddler dyads living in low-income homes in the U.S.

Biological sensitivity to context in Pakistani preschoolers: Hair cortisol and family wealth are interactively associated with girls' cognitive skills

Many young children in low- and middle-income countries (LMICs) face heightened risk for experiencing environmental adversity, which is linked with poorer developmental outcomes. Children's stress physiology can shed light on why children are differentially susceptible to adversity. However, no known studies have examined whether links between adversity and children's development are moderated by children's stress physiology in LMICs. The present study revealed significant interactive effects of hair cortisol concentrations, an index of chronic physiological stress regulation, and family wealth on preschoolers' cognitive skills in rural Pakistan. In a sample of 535 4-year-old children (n = 342 girls), we found significant associations between family wealth and direct assessments of verbal intelligence, pre-academic skills, and executive functions only in girls with lower hair cortisol concentrations. Specifically, girls with lower cortisol concentrations displayed greater cognitive skills if they came from relatively wealthier families, but lower cognitive skills if they came from very poor families. There were no significant associations among boys. Results provide evidence of biological sensitivity to context among young girls in a LMIC, perhaps reflecting, in part, sex differences in daily experiences of environmental adversity.

Long-term stress levels are synchronized in dogs and their owners

This study reveals, for the first time, an interspecific synchronization in long-term stress levels. Previously, acute stress, has been shown to be highly contagious both among humans and between individuals of other species. Here, long-term stress synchronization in dogs and their owners was investigated. We studied 58 dog-human dyads and analyzed their hair cortisol concentrations (HCC) at two separate occasions, reflecting levels during previous summer and winter months. The personality traits of both dogs and their owners were determined through owner-completed Dog Personality Questionnaire (DPQ) and human Big Five Inventory (BFI) surveys. In addition, the dogs’ activity levels were continuously monitored with a remote cloud-based activity collar for one week. Shetland sheepdogs (N = 33) and border collies (N = 25), balanced for sex, participated, and both pet dogs and actively competing dogs (agility and obedience) were included to represent different lifestyles. The results showed significant interspecies correlations in long-term stress where human HCC from both summer and winter samplings correlated strongly with dog HCC (summer: N = 57, χ² = 23.697, P < 0.001, β = 0.235; winter: N = 55, χ² = 13.796, P < 0.001, β = 0.027). Interestingly, the dogs’ activity levels did not affect HCC, nor did the amount of training sessions per week, showing that the HCC levels were not related to general physical activity. Additionally, there was a seasonal effect in HCC. However, although dogs’ personalities had little effects on their HCC, the human personality traits neuroticism, conscientiousness, and openness significantly affected dog HCC. Hence, we suggest that dogs, to a great extent, mirror the stress level of their owners.