Emotion regulation moderates the association between parent and child hair cortisol concentrations

Early life stress, literacy and dyslexia: an evolutionary perspective

Stress and learning co-evolved in parallel, with their interdependence critical to the survival of the species. Even today, the regulation of moderate levels of stress by the central autonomic network (CAN), especially during pre- and post-natal periods, facilitates biological adaptability and is an essential precursor for the cognitive requisites of learning to read. Reading is a remarkable evolutionary achievement of the human brain, mysteriously unusual, because it is not pre-wired with a genetic address to facilitate its acquisition. There is no gene for reading. The review suggests that reading co-opts a brain circuit centered in the left hemisphere ventral occipital cortex that evolved as a domain-general visual processor. Its adoption by reading depends on the CAN's coordination of the learning and emotional requirements of learning to read at the metabolic, cellular, synaptic, and network levels. By stabilizing a child's self-control and modulating the attention network's inhibitory controls over the reading circuit, the CAN plays a key role in school readiness and learning to read. In addition, the review revealed two beneficial CAN evolutionary adjustments to early-life stress "overloads" that come with incidental costs of school under-performance and dyslexia. A short-term adaptation involving methylation of the FKBP5 and NR3C1 genes is a liability for academic achievement in primary school. The adaptation leading to dyslexia induces alterations in BDNF trafficking, promoting long-term adaptive fitness by protecting against excessive glucocorticoid toxicity but risks reading difficulties by disruptive signaling from the CAN to the attention networks and the reading circuit.

Examining parental stress and its link to hair cortisol and DHEA levels in kindergartners

BACKGROUND

Parental work-family conflict (WFC) and parental household income have been linked to negative outcomes for children. So far, no study has associated these two stressors with the hair concentration of cortisol (HCC) and dehydroepiandrosterone (DHEA) in kindergarteners as a measurement of their objective stress.

METHODS AND MEASURES

44 children (40.91% female) with a mean age of 5.16 years and their parents participated in this cross-sectional study. Children's cortisol and DHEA measurements reflected the hormones produced over the past two months. Parents filled out questionnaires concerning their WFC and parenting behavior.

RESULTS

Higher maternal WFC and a lower parental net household income were negatively associated with the DHEA and positively with HCC/DHEA ratio of their children. No significant associations were found between HCC and any included variables. Paternal WFC had no impact on the stress hormones and negatively affected parenting behavior of both parents. Levels of stress hormones were not correlated with parenting behavior.

CONCLUSION

The present results indicated a higher stress exposure in children of mothers with a higher WFC and lower net household income. Conceivably, this may have led to an accumulation of allostatic load. Potential influences of demographic variables on the children's hormones are discussed.

Concurrent and prospective associations between family socioeconomic status, social support and salivary diurnal and hair cortisol in adolescence

BACKGROUND

Exposure to socioeconomic adversity is hypothesized to impact hypothalamic-pituitary-adrenal (HPA) axis activity and cortisol secretion, but existing evidence is inconsistent. Yet, few studies have investigated this association using a developmental approach that considers potential protective contextual factors. This study examined the role of stability and changes in family socioeconomic status (SES) in the prediction of multiple cortisol indicators and tested whether social support moderated these associations.

METHODS

Participants were part of a population-based sample of twin pairs recruited at birth. Family SES was assessed in early childhood (ages 0-5) and mid-adolescence (age 14). Social support was assessed at ages 14 and 19. Diurnal cortisol (n = 569) was measured at age 14 at awakening, 30 min later, in the afternoon and evening over four non-consecutive days. Hair cortisol concentration (HCC, n = 704) was measured at age 19. All data were collected before the pandemic and multilevel regression models were conducted to account for the nested data structure.

RESULTS

Youth exposed to lower family SES levels in childhood and mid-adolescence had a flatter diurnal slope and higher HCC compared with those who experienced upward socioeconomic mobility in mid-adolescence. Contrastingly, mid-adolescence SES showed no association with the diurnal slope or HCC for youth from higher-SES households in early childhood. Moreover, youth raised in higher-SES families in early childhood had a higher CAR in mid-adolescence if they reported greater social support in mid-adolescence. Social support also moderated the SES-cortisol association in mid-adolescence, with higher-SES youth showing higher awakening cortisol secretion when reporting more social support.

CONCLUSIONS

Our findings support the hypothesis that early socioeconomic adversity sensitizes HPA axis activity to later socioeconomic disadvantage, which may bear consequences for socioemotional and behavioral functioning.

Major depressive disorder and bistability in an HPA-CNS toggle switch

Major depressive disorder (MDD) is the most common psychiatric disorder. It has a complex and heterogeneous etiology. Most treatments take weeks to show effects and work well only for a fraction of the patients. Thus, new concepts are needed to understand MDD and its dynamics. One of the strong correlates of MDD is increased activity and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis which produces the stress hormone cortisol. Existing mathematical models of the HPA axis describe its operation on the scale of hours, and thus are unable to explore the dynamic on the scale of weeks that characterizes many aspects of MDD. Here, we propose a mathematical model of MDD on the scale of weeks, a timescale provided by the growth of the HPA hormone glands under control of HPA hormones. We add to this the mutual inhibition of the HPA axis and the hippocampus and other regions of the central nervous system (CNS) that forms a toggle switch. The model shows bistability between euthymic and depressed states, with a slow timescale of weeks in its dynamics. It explains why prolonged but not acute stress can trigger a self-sustaining depressive episode that persists even after the stress is removed. The model explains the weeks timescale for drugs to take effect, as well as the dysregulation of the HPA axis in MDD, based on gland mass changes. This understanding of MDD dynamics may help to guide strategies for treatment.

Preschool-aged children's hair cortisol and parents' behavior, psychopathology, and stress

Parental factors, including parenting behavior, parent mental health, and parent stress, are associated with child stress. More recently, studies have shown that these parental factors may also be associated with children's hair cortisol concentration (HCC). HCC is a novel biomarker for chronic stress. HCC indexes cumulative cortisol exposure thereby reflecting longer-term stress reactivity. Although HCC is associated with a range of problems in adults such as depression, anxiety, appraisal of stressful events, and diabetes, studies investigating HCC in children have been inconsistent, with particularly little information about parental factors and HCC. As chronic stress may have long-term physiological and emotional effects on children, and parent-based interventions can reduce these effects, it is important to identify parental factors that relate to children's HCC. The aim of this study was to examine associations between preschool-aged children's physiological stress measured via HCC and mother- and father-reported parenting behavior, psychopathology, and stress. Participants included N = 140 children ages 3-5-years-old and their mothers (n = 140) and fathers (n = 98). Mothers and fathers completed questionnaire measures on their parenting behavior, depressive and anxiety symptoms, and perceived stress. Children's HCC was assessed by processing small hair samples. HCC levels were higher in boys compared to girls, and higher in children of color compared to white children. There was a significant association between children's HCC and fathers' authoritarian parenting. Children's HCC was positively associated with physical coercion, a specific facet of fathers' authoritarian parenting, even after accounting for sex of the child, race/ethnicity of the child, stressful life events, fathers' depression, fathers' anxiety, and fathers' perceived stress. In addition, there was a significant interaction between higher levels of both mothers' and fathers' authoritarian parenting and children's HCC. Children's HCC was not significantly related to mothers' and fathers' anxiety and depression or mothers' and fathers' perceived stress. These findings contribute to the large literature that links harsh and physical parenting practices with problematic outcomes in children.

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.

Daily COVID-19 Stressor Effects on Children's Mental Health Depend on Pre-pandemic Peer Victimization and Resting Respiratory Sinus Arrhythmia

Children's risk of poorer mental health due to the COVID-19 pandemic may depend on risk and protective factors heading into the pandemic. This study examined same-day associations between COVID-19 stressors and children's mental health using a daily diary design across 14 days, and considered the moderating roles of pre-pandemic peer victimization experiences and resting respiratory sinus arrhythmia (RSA; an indicator of cardiac regulatory capacity). Forty-nine Canadian children aged 8-13 years (Mage = 10.69, 29 girls) participated in the final wave of a longitudinal study just prior to the pandemic and a daily diary extension during the pandemic (N = 686 pandemic measurement occasions). Multilevel modeling indicated that children had poorer mental health on days when they experienced a COVID-19 stressor (e.g., virtual academic difficulties, social isolation). A three-way interaction indicated that this association was stronger for those with higher pre-pandemic peer victimization experiences and lower pre-pandemic resting RSA; however, highly victimized children with higher resting RSA did not experience poorer mental health on days with COVID-19 stressors. Findings offer preliminary insights into the preceding risk and protective factors for children's mental health amidst major subsequent stress.

Association between the timing of family socioeconomic deprivation and adolescence hair cortisol among adolescent twins: A study of the genetic and environmental processes involved

BACKGROUND

While evidence shows that lower socioeconomic status (SES) is related to dysregulated hair cortisol concentration (HCC), the genetic and environmental processes underlying this association remain understudied.

OBJECTIVES

(1) to examine whether childhood and adolescence SES are phenotypically related to late adolescence HCC and to what extent these associations are explained by common underlying genetic factors (2) to estimate whether the genetic and environmental etiology of HCC varies according to SES and the timing of these experiences.

METHODS

Participants were 422 twin pairs for whom SES was measured in childhood (ages 0-5 years) and adolescence (age 14 years). Hair cortisol was assessed at age 19.

RESULTS

Additive genetic factors explained 39% of variability in HCC, whereas nonshared environmental factors accounted for the remaining 61%. A significant negative association emerged between HCC and family SES assessed in adolescence (β=-.11,p = .02), which was entirely explained by common underlying environmental influences. We also found evidence of stronger genetic contributions to HCC among youths who lived in more disadvantaged households during childhood in comparison to those from wealthier backgrounds.

CONCLUSIONS

This study provides first-time evidence that the association between adolescence SES and HCC is environmentally-explained and that genetic influences underlying HCC are not uniformly distributed across the family SES continuum measured during childhood. These findings may pave the way for a fuller understanding of the impact of early adversity on HPA axis activity.

Circulating FGF21 vs. Stress Markers in Girls during Childhood and Adolescence, and in Their Caregivers: Intriguing Inter-Relations between Overweight/Obesity, Emotions, Behavior, and the Cared-Caregiver Relationship

Fibroblast growth factor-21 (FGF21) acts on several brain regions, including the hypothalamic paraventricular nucleus, which is involved in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study was to investigate the interrelations between FGF21 and stress indices in girls, as well as in their caregivers. 78 girls, aged between 5 and 15 years, were studied; 50 of them were overweight and obese (OB) and 28 in the control group (C). Serum FGF21 and hair and diurnal salivary cortisol were measured. Children participants filled in the Children’s Depression Inventory (CDI) and the State-Trait Anxiety Inventory for Children (STAIC), while their caregivers filled in the State-Trait Anxiety Inventory (STAI), the Perceived Stress Scale (PSS), and the Holmes-Rahe Stress Events Scale (HRSES). The OB group girls had significantly higher levels of FGF21 than the C group (p < 0.001). In contrast to the C group, in whom FGF21 levels were positively correlated with both hair and salivary AUCg cortisol concentrations (p = 0.045 and p = 0.007, respectively), no such correlations were observed in the OB group. In the caregivers of the OB group, STAI-state (r = 0.388, p = 0.008), STAI-trait (r = 0.4, p = 0.006), PSS (r = 0.388, p = 0.008), and HRSES (r = 0.358, p = 0.015) scores, all correlated positively with the FGF21 levels of the children under their care. FGF21 concentrations positively correlated with hair and salivary cortisol levels in the C group only. These findings may represent an interesting correlation dictated by bi-directional empathy links between the primary caregivers and the children under their care.

A Cross-Cultural Examination of the Role of Youth Emotion Regulation in Mentoring Relationships

Youth mentoring programs have grown in popularity, both within the United States (U.S.) and abroad, as an intervention to support youth with common behavioral and emotional difficulties. However, it is unclear whether certain dimensions of youth risk may diminish the positive impact of formalized mentoring relationships. The current study therefore examined whether youth emotion regulation, a transdiagnostic risk factor for both externalizing and internalizing behavioral difficulties, predicted mentoring relationship quality and the likelihood of early match closure. Participants included 1,298 randomized mentor-youth dyads from two nationwide mentoring programs, one with chapters across the U.S. (youth: 56% female; 37% White), and another with chapters across Mexico (youth: 49% female; 100% non-Indigenous). At baseline, youth completed the Emotion Regulation Questionnaire for Children and Adolescents (ERQ-CA). At program completion, youth and mentors completed measures of mentoring relationship quality. Multigroup structural equation models of youth outcomes revealed that greater youth use of cognitive reappraisal predicted better mentoring relationship quality in both countries when co-varying for sex, and that this relationship was stronger for mentor-youth pairs in the U.S. compared to those in Mexico. These findings have important implications for understanding the ways in which youth characteristics might shape the quality and impact of mentoring relationships across different cultural settings.

Atypical maternal interaction is associated with elevated levels of hair cortisol in children

The quality of maternal caregiving is an important factor in the healthy development of a child. One consequence of prolonged insensitive and atypical maternal interaction behavior (e.g., withdrawing from interactions with the child and role-reversal, i.e., the takeover of the parental role or parts of it by the child) in mother-child-dyads can cause alteration of the child's stress response system. Higher salivary cortisol concentrations were reported in infants and toddlers directly after negative interactions with their parents. However, no study to date has examined the association between atypical maternal interaction behavior and hair cortisol concentrations (HCC) in infants. Here, we studied the association of maternal interaction behavior with HCC of the child. Mother-child dyads (N = 112) participated in the longitudinal study My Childhood-Your Childhood. The AMBIANCE scale and its subscales were used to assess atypical maternal interaction behavior during the Strange Situation Procedure. Chronic stress levels in the child were assessed by HCC of 3 cm hair strands at the age of 12 months. Maternal educational level (operationalized in highest education level) served as a control variable. Robust multiple linear regression analyses revealed that role/boundary confusion was associated with HCC, i.e., the higher atypical interaction behavior of the mother the higher the HCC in the children. By measuring hair cortisol in this study, it is possible to determine the average long-term activity of the child's stress response system.Thus, atypical maternal interaction behavior could be a risk factor for persistent stress in children, contributing to a higher risk for negative health outcomes in later life. The results of this study highlight the importance of early intervention programs that focus on the relationship between mother and child.

Social cognition and cortisol in the general population: A systematic review and meta-analysis

This systematic review examines the evidence on the association between social cognition and cortisol in the general population. Literature was searched in six databases. Of the 401 studies identified, meta-analyses were conducted on 46 effect sizes (Pearson's correlation coefficients) from 19 studies, supplemented by a narrative review. Pooled estimates suggest that better emotion control is associated with increased cortisol concentrations [r = 0.083, 95% CI (0.033, 0.132)]. Emotion recognition or empathy were not significantly associated with cortisol concentrations [r = 0.072, 95% CI (-0.020, 0.165) and r = 0.004, 95% CI (-0.061, 0.068) respectively]. Subgroup analyses showed that the association between emotion control and cortisol concentrations is significant in males, for morning cortisol, when the cortisol data are transformed to correct for skewed distributions, or when participants are instructed to avoid food and drink intake for at least one hour before sample collection. There was no evidence for an association between social cognition with diurnal cortisol slope or cortisol awakening response. More validation work with greater standardization of methodological procedures is required.

Impacts of Parental Burnout on Chinese Youth's Mental Health: The Role of Parents' Autonomy Support and Emotion Regulation

Parental burnout is a state that parents experience overwhelming exhaustion in their parental role. Given the detrimental impacts of parents' stress on adolescent development, youth may suffer from undesirable emotional adjustment due to parental burnout. Therefore, it is key to understand the underlying mechanisms through which parental burnout may play a role in youth's mental health and identify protective factors that may reduce the potential negative impacts. Using a sample of 442 Chinese parent-adolescent dyads (Mean age of youth = 13.35 years; 50% girls), this two-wave longitudinal study examined how parental burnout contributes to youth's mental health over the span of two months. Moreover, the current research investigated the potential mediating role of autonomy support and the potential moderating role of emotion regulation in the links between parental burnout and youth's mental health. The results showed that greater parental burnout was predictive of youth's greater depressive and anxiety symptoms two months later, and such effects were partially mediated by less autonomy-supportive parenting. Notably, the negative effects of parental burnout on autonomy-supportive parenting and youth's mental health were not significant when parents used more cognitive reappraisal to regulate their emotions. These findings demonstrate the underlying mechanisms of how parental burnout affects youth's mental health over time and highlight the protective role of healthy emotion regulation against parental burnout.

Stress in the onset and aggravation of learning disabilities

Despite substantial grounds for such research, the role of chronic exposure to stressors in the onset and aggravation of learning disabilities (LDs) is largely unexplored. In this review, we first consider the hormonal, (epi)genetic, and neurobiological mechanisms that might underlie the impact of adverse childhood experiences, a form of chronic stressors, on the onset of LDs. We then found that stress factors combined with feelings of inferiority, low self-esteem, and peer victimization could potentially further aggravate academic failures in children with LDs. Since effective evidence-based interventions for reducing chronic stress in children with LDs could improve their academic performance, consideration of the role of exposure to stressors in children with LDs has both theoretical and practical importance, especially when delivered in combination with academic interventions.

Associations between social adversity and young children's hair cortisol: A systematic review

Psychosocial and socioeconomic adversity in early childhood (termed 'social adversity') can have lifelong detrimental effects on health and development. Physiological stress is one proposed mechanism by which social adversity 'gets under the skin'. There is substantial research interest in whether hair cortisol, a biomarker proposed to measure the cumulative physiological stress response over time, can illustrate this mechanism. As a result, a growing number of studies have tested for associations between indicators of social adversity and child hair cortisol. The aim of this paper is to conduct a comprehensive, systematic review of the evidence for associations between indicators of social adversity and hair cortisol, specifically in young children (birth to 8 years) published any time up to 31 December 2019. The literature search identified 44 published studies that met inclusion criteria. The studies examined associations between one or more indicators of social adversity and child hair cortisol across 35 independent cohorts comprising 8370 children. Indicators of adversity examined in the identified literature included socioeconomic factors (e.g. low parental education, low income and unemployment), psychosocial factors (e.g. parent stress, poor mental health and family violence), and children's direct exposure to maltreatment, abuse and stressful events. Across all indicators of adversity, a total of 142 associations with hair cortisol were examined. Evidence of associations was limited and inconsistent; 34/142 (24%) showed evidence of a positive association between adversity and higher hair cortisol, 8/142 (6%) showed a negative association, and more than two thirds (100/142, 70%) of all examined associations were null. The collective evidence appears insufficient to conclude that there is a relationship between social adversity and hair cortisol, as a measure of physiological stress response, in young children.

Hair cortisol in mother-child dyads: examining the roles of maternal parenting and stress in the context of early childhood adversity

Physiological stress is thought to be one way that early adversity may impact children's health. How this occurs may be related to parental factors such as mothers' own stress and parenting behaviour. Hair cortisol offers a novel method for examining long-term physiological stress in mother-child dyads. The current study used hair cortisol to examine the role that maternal physiological stress and parenting behaviours play in explaining any effects of adversity on young children's physiological stress. This cross-sectional study comprised 603 mother-child dyads at child age 2 years, recruited during pregnancy for their experience of adversity through an Australian nurse home visiting trial. Hair cortisol data were available for 438 participating mothers (73%) and 319 (53%) children. Confirmatory factor analysis was used to define composite exposures of economic (e.g. unemployment, financial hardship) and psychosocial (e.g. poor mental health, family violence) adversity, and positive maternal parenting behaviour (e.g. warm, responsive). Structural equation modelling examined maternal mediating pathways through which adversity was associated with children's physiological stress. Results of the structural model showed that higher maternal and child physiological stress (hair cortisol) were positively associated with one another. Parenting behaviour was not associated with children's physiological stress. There was no evidence of any mediating pathways by which economic or psychosocial adversity were associated with children's physiological stress. The independent association identified between maternal and child hair cortisol suggests that young children's physiological stress may not be determined by exogenous environmental exposures; endogenous genetic factors may play a greater role.

Cortisol and socioeconomic status in early childhood: A multidimensional assessment

The hypothalamic-pituitary-adrenal (HPA) axis is sensitive to early life stress, with enduring consequences for biological stress vulnerability and health (Gunnar & Talge, 2008). Low socioeconomic status (SES) is associated with dysregulation of the stress hormone cortisol in early childhood. However, a mechanistic understanding of this association is lacking. Multidimensional assessment of both SES and cortisol is needed to characterize the intricate relations between SES and cortisol function in early childhood. We assessed parent-reported family income, parent education, occupational prestige, neighborhood risk, food insecurity, and household chaos for 12-month-old infants (N = 90) and 3.5-year-old children (N = 91). Hair cortisol concentration (HCC) was obtained from parent and child, indexing chronic biological stress, and diurnal salivary cortisol was measured in the children. Controlling for parent HCC, parent education uniquely predicted infant and child HCC and, in addition, neighborhood risk uniquely predicted infant HCC. Household chaos predicted bedtime salivary cortisol concentration (SCC) for both infants and children, and infant daily cortisol output. Food insecurity was associated with flattened cortisol slope in 3.5-year-old children. Parental sensitivity did not mediate relations between SES and cortisol. Results highlight the utility of SES measures that index unpredictable and unsafe contexts, such as neighborhood risk, food insecurity, and household chaos.

Examining the role of socioeconomic status and temperament in the hair cortisol levels of infants

Socioeconomic status (SES) appears to be an important contextual factor in children's developmental outcomes, including their responses to stress. However, some children are more susceptible to its effects than others. Hair cortisol is a newer method of assessing the activity of the HPA axis, providing cumulative cortisol levels. The present article examined whether temperament (negative emotionality) moderates the association between an SES index and the hair cortisol concentration (HCC) of infants. Sixty infants from 6 to 15 months of age were recruited, of which 49 had sufficient hair for cortisol analysis. The SES index was calculated from the education levels of the mothers, family income, and a scale measuring the quality of the home environment. Negative emotionality was measured with the three sub-scales of the Infant Behavior Questionnaire (falling reactivity, distress to limitations, and fear). Among infants low in negative emotionality, there was no association between SES and cortisol. In contrast, among those high in negative emotionality, a significant association was obtained. These infants showed lower levels of HCC in lower-SES environments. The findings suggest that there are individual differences in reacting to the environment, and low levels of cortisol (not high) were found in susceptible infants in lower-SES families.

Caregiver depression is associated with hair cortisol in a low-income sample of preschool-aged children

BACKGROUND

Caregiver depression and child temperamental characteristics such as effortful control have been associated with child dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. Hair cortisol concentrations (HCC) has been increasingly adopted as an integrated marker of HPA axis activity. This study examined the associations between caregiver depressive symptoms, caregiver social support, child effortful control, and child HCC in a sample of a high-risk, low-income preschool-aged children.

METHODS

154 caregivers comprised mostly of mothers and their children (2-to-5 years) who were enrolled in a birth cohort study conducted in poor urban neighborhoods of São Paulo, Brazil. Through personal interviews at their homes, caregivers provided ratings of their psychosocial experiences and of their child's behavior. Hair was sampled from children with at least a 3-cm hair length.

RESULTS

In a multivariable regression analysis, an unadjusted model showed child age to be negatively associated with HCC (β = -0.32, p < .001). The adjusted model, which accounted for child age and sex, showed a positive relationship between caregiver depressive symptoms and HCC (β = 0.22, p < .01). Caregiver social support and child effortful control were not associated with HCC.

CONCLUSIONS

The elevated HCC among children with caregivers reporting greater depression risk is consistent with prior findings showing elevated HCC among children exposed to persistent stress. Stabilization of child HCC may be occurring within preschool children given the negative association between HCC and age. Greater research is needed to determine whether the effects of caregiver social support and effortful control can be captured through HCC.

Minimally-invasive methods for examining biological changes in response to chronic stress: A scoping review

BACKGROUND

Nurse researchers are increasingly interested in incorporating biological indicators related to chronic stress, or repeated or constant exposure to psychological stressors. Minimally invasive collection methods may improve access to vulnerable populations.

OBJECTIVE

To map biological indicators measured through minimally invasive methods investigating biological changes in response to chronic stress.

DESIGN, DATA SOURCES, AND METHODS

The paper seeks to answer two questions: What are the characteristics of the minimally-invasive methods used to measure the biological correlates of chronic stress? What are the limitations regarding the use of the minimally-invasive methods and/or biological indicators identified above? Authors completed a scoping review following guidelines from the Joanna Briggs Institute Manual and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews. A literature search was completed in PubMed, PsycINFO, and Scopus. 2518 articles were screened and 145 studies were included. Data were extracted using a standardized extraction tool, compiled, and coded.

RESULTS

Studies included minimally-invasive methods to measure the hypothalamic-adrenal-pituitary axis (N = 173), immune and inflammatory markers (N = 118), and adult neurogenesis (N = 6). Cortisol was most frequently measured (N = 136), usually in saliva (N = 86). Studies included a variety of limitations for the methods and indicators, including concerns about timing and accuracy of collection, frequency of sampling, and controlling for acute stressors.

CONCLUSIONS

Nurse researchers have access to many minimally-invasive methods to measure altered biological processes related to chronic stress. A gap identified by this review is the paucity of minimally-invasive methods for investigating neurogenesis; the measurement of brain derived neurotrophic factor in plasma is a distal proxy and further research is needed to test the response of peripheral levels to psychosocial stress interventions. Additionally, while this scoping review allows nurse researchers to consider possible biological indicators to include in their research, future research is still needed on some of the basic premises of stress research, including agreement on the conceptualization of chronic stress.