Allostatic load: Developmental and conceptual considerations in a multi-system physiological indicator of chronic stress exposure

The mediating role of child delay of gratification in the link between early and prolonged poverty exposure and adolescent allostatic load

Early and prolonged exposure to poverty disrupts biological processes associated with the body's stress response system, leading to long-term negative health outcomes, including obesity, autoimmune disorders, and cardiovascular disease. Allostatic load (AL), a composite measure of chronic stress on the body, is a robust predictor of subsequent health outcomes. However, developmental research examining the associations of early poverty exposure with AL in adolescence, as well as the underlying mechanisms of influence is limited. Early poverty exposure also impedes healthy development of child self-regulation, which may increase risk for high AL in adolescence, but this mechanistic pathway has not yet been tested. We used data from the national Study of Early Child Care and Youth Development (SECCYD) to examine the longitudinal associations between prolonged poverty exposure in early childhood (0-3 years) and AL in adolescence (age 15). We also tested the mediating role of child delay of gratification, a behavioral measure of self-regulation (at age 54 months), in the potential association between early poverty exposure and adolescent AL. Accounting for model covariates (i.e., child biological sex and race-ethnicity) and individual differences in child delay of gratification, early and prolonged poverty exposure was significantly associated with higher AL at age 15. The indirect effect through child delay of gratification was not significant, but the individual pathways of the indirect effect were significant, and the overall direct association of early poverty exposure with adolescent AL was significant. Our findings show that prolonged exposure to poverty in early childhood (0-3 years) can have significant negative associations with both child delay of gratification (at 54 months) and AL (at age 15). Given that the detrimental impacts of poverty exposure can be detected at an early age, targeted prevention efforts (e.g., anti-poverty programs such as cash assistance programs) may be able to offset some of the risks of early poverty exposure on self-regulation and AL.

Allostatic Load in Childhood, Adolescence, and Young Adulthood: Are Assumptions of Measurement Invariance Warranted?

OVERVIEW

Allostatic load represents the cumulative toll of chronic mobilization of the body's stress response systems, as indexed by biomarkers. Higher levels of stress and disadvantage predict higher levels of allostatic load, which, in turn, predict poorer physical and mental health outcomes. To maximize the efficacy of prevention efforts, screening for stress- and disadvantage-associated health conditions must occur before middle age-that is, during childhood, adolescence, and young adulthood. However, this requires that models of allostatic load display properties of measurement invariance across age groups. Because most research on allostatic load has featured older adults, it is unclear if these requirements can be met.

METHODS

To address this question, we fit a series of exploratory and confirmatory analytic models to data on eight biomarkers using a nationally representative sample of N = 4260 children, adolescents, and young adults drawn from the National Health and Nutrition Examination Survey dataset.

RESULTS

Exploratory and confirmatory models indicated that, consistent with allostatic load theory, a unidimensional model was a good fit to the data. However, this model did not display properties of measurement invariance; post-hoc analyses suggested that the biomarkers included in the final confirmatory model were most strongly intercorrelated among young adults and most weakly intercorrelated among adolescents.

CONCLUSIONS

These results underscore the importance of testing assumptions about measurement invariance in allostatic load before drawing substantive conclusions about stress, disadvantage, and health by directly comparing levels of allostatic load across different stages of development, while underscoring the need to expand investigations of measurement invariance to samples of longitudinal data.

Continuity of mental disorders in children with chronic physical illness

Data on the chronicity of mental disorder in children with chronic physical illness (CPI) are limited. We examined the prevalence and predictors of homotypic and heterotypic continuity of mental disorder in children with CPI. A sample of 263 children aged 2-16 years with physician-diagnosed CPI were recruited from outpatient clinics (e.g., dermatology, respiratory) at a Canadian pediatric academic hospital and followed for 24 months. Parent and child-reported mental disorders (mood, anxiety, behavioral, attention-deficit hyperactivity disorder [ADHD]) were assessed using the Mini International Neuropsychiatric Interview for Children and Adolescents at baseline, 6, 12, and 24 months. Marginal regression models were computed to identify clinical, parent, and demographic factors associated with mental comorbidity over time. Mental disorder was observed in 24-27% of children with CPI based on child reports and 35-39% based on parent reports. Parent-reported models revealed significant homotypic continuity for all mental disorders (ORs = 4.2-9.5), and heterotypic continuity between mood and anxiety disorders (OR = 2.2), ADHD and behavioral disorders (OR = 5.1), and behavioral and each mental disorder (ORs = 6.7-8.4). Child-reported models revealed significant homotypic continuity for mood (OR = 8.8) and anxiety disorder (OR = 6.0), and heterotypic continuity between anxiety and mood disorders (OR = 12.4). Child disability (ORs = 1.3-1.5) and parent psychopathology (ORs = 1.2-1.8) were the most consistent predictors of both child- and parent-reported mental disorder over time. Mental comorbidity was prevalent and persistent in children with CPI with homotypic and heterotypic continuity common across informants. Child disability and parent psychopathology may be priority targets within integrated family-centered models of care to prevent mental comorbidity in children with CPI.

Weight stigma and allostatic load in adults: protocol for a scoping review

INTRODUCTION

Weight-related stigma (WS) has been associated with adverse psychosocial and physical health effects. Despite the relationship between WS and allostatic load, there are no integrative reviews of this association. This scoping review aims to provide a comprehensive overview of the relationship between allostatic load biomarkers associated with WS by identifying gaps in this topic and proposing recommendations for future research.

METHODS AND ANALYSIS

This protocol was guided by the methodological framework of Arksey and O'Malley and the Joanna Briggs Institute (JBI). The research questions were based on the population-concept-context framework. Studies in adults diagnosed as overweight or obese, exposed to WS and assessing the association between WS and biomarkers of allostatic load will be included. A search will be conducted in Medline (Ovid), PsycINFO (Ovid), Scopus (Elsevier), Cochrane Library (Wiley) and Google Scholar. The search strategy will be conducted in three stages, based on the JBI recommendation with the MESH terms "Social Stigma," "Weight Prejudice," "Biomarkers," "Allostasis," "Adults" and related terms. Data extraction will be done with a template adapted from JBI. The search strategy and selection process results will be presented in a flow chart and summarised in the text. The main results will be presented in a descriptive synthesis.

ETHICS AND DISSEMINATION

Ethics review and approval are not required. The results will be disseminated through peer-reviewed publications, conferences, congresses or symposia.

Allostatic load in early adolescence: gene / environment contributions and relevance for mental health

Background

Allostatic load is the cumulative "wear and tear" on the body due to chronic adversity. We aimed to test poly-environmental (exposomic) and polygenic contributions to allostatic load and their combined contribution to early adolescent mental health.

Methods

We analyzed data on N = 5,035 diverse youth (mean age 12) from the Adolescent Brain Cognitive Development Study (ABCD). Using dimensionality reduction method, we calculated and overall allostatic load score (AL) using body mass index [BMI], waist circumference, blood pressure, blood glycemia, blood cholesterol, and salivary DHEA. Childhood exposomic risk was quantified using multi-level environmental exposures before age 11. Genetic risk was quantified using polygenic risk scores (PRS) for metabolic system susceptibility (type 2 diabetes [T2D]) and stress-related psychiatric disease (major depressive disorder [MDD]). We used linear mixed effects models to test main, additive, and interactive effects of exposomic and polygenic risk (independent variables) on AL (dependent variable). Mediation models tested the mediating role of AL on the pathway from exposomic and polygenic risk to youth mental health. Models adjusted for demographics and genetic principal components.

Results

We observed disparities in AL with non-Hispanic White youth having significantly lower AL compared to Hispanic and Non-Hispanic Black youth. In the diverse sample, childhood exposomic burden was associated with AL in adolescence (beta=0.25, 95%CI 0.22-0.29, P<.001). In European ancestry participants (n=2,928), polygenic risk of both T2D and depression was associated with AL (T2D-PRS beta=0.11, 95%CI 0.07-0.14, P<.001; MDD-PRS beta=0.05, 95%CI 0.02-0.09, P=.003). Both polygenic scores showed significant interaction with exposomic risk such that, with greater polygenic risk, the association between exposome and AL was stronger. AL partly mediated the pathway to youth mental health from exposomic risk and from MDD-PRS, and fully mediated the pathway from T2D-PRS.

Conclusions

AL can be quantified in youth using anthropometric and biological measures and is mapped to exposomic and polygenic risk. Main and interactive environmental and genetic effects support a diathesis-stress model. Findings suggest that both environmental and genetic risk be considered when modeling stress-related health conditions.

Allostatic Load in Children and Adolescents: A Systematic Review

INTRODUCTION

The concept of allostatic load encompasses the cumulative effects of both ordinary daily life events as well as major challenges, and also includes related health-damaging behavior. Allostatic overload ensues when environmental challenges exceed the individual's ability to cope. Identification of allostatic load is carried out through the use of biomarkers and clinimetric criteria. Studies are increasingly reported on allostatic load in younger populations, yet a systematic review is missing.

OBJECTIVE

The aim of the present systematic review was to summarize the current knowledge on allostatic load/overload among children and adolescents.

METHODS

PubMed, PsycINFO, Web of Science, and the Cochrane Library were searched from inception to April 2023. A manual search of the literature was also performed. We considered only studies in which allostatic load or overload were adequately described and assessed in either clinical or non-clinical populations younger than 18 years.

RESULTS

A total of 38 original investigations were included in this systematic review. Studies reported an association between allostatic load and sociodemographic characteristics (e.g., poverty, ethnicity, perceived discrimination, adverse childhood experiences) and environmental factors, as well as consequences of allostatic load on both physical and mental health among children and adolescents.

CONCLUSIONS

The findings indicate that greater allostatic load is associated with poorer health outcomes in both clinical and non-clinical pediatric populations, with possible enduring effects. The results support the clinical utility of the transdiagnostic identification of allostatic load and overload in children and adolescents across a variety of settings, with a number of potential clinical implications.

Multigenerational adversity impacts on human gut microbiome composition and socioemotional functioning in early childhood

Adversity exposures in the prenatal and postnatal period are associated with an increased risk for psychopathology, which can be perpetuated across generations. Nonhuman animal research highlights the gut microbiome as a putative biological mechanism underlying such generational risks. In a sample of 450 mother-child dyads living in Singapore, we examined associations between three distinct adversity exposures experienced across two generations-maternal childhood maltreatment, maternal prenatal anxiety, and second-generation children's exposure to stressful life events-and the gut microbiome composition of second-generation children at 2 y of age. We found distinct differences in gut microbiome profiles linked to each adversity exposure, as well as some nonaffected microbiome features (e.g., beta diversity). Remarkably, some of the microbial taxa associated with concurrent and prospective child socioemotional functioning shared overlapping putative functions with those affected by adversity, suggesting that the intergenerational transmission of adversity may have a lasting impact on children's mental health via alterations to gut microbiome functions. Our findings open up a new avenue of research into the underlying mechanisms of intergenerational transmission of mental health risks and the potential of the gut microbiome as a target for intervention.

Physical activity is associated with allostatic load: Evidence from the National Health and Nutrition Examination Survey

We determined the associations between physical activity and allostatic load, and whether it is a modifiable factor related to allostatic load. We obtained data from the National Health and Nutrition Examination Survey (NHANES) database collected between 2017 and March 2020. The relationship between physical activity and allostatic load was examined using a logistic regression model. In the unadjusted model, physical activity level was associated with allostatic load index (odds ratio [OR] = 0.664, 95% confidence interval [CI]: 0.550, 0.802, P＜0.001), with this relationship being retained in the adjusted model (OR = 0.739, 95%CI: 0.603, 0.907; P = 0.004). Sedentary behaviour was also related to allostatic load index (OR = 1.236, 95%CI: 1.005, 1.520; P = 0.044). Our findings indicated that sufficient physical activity is associated with a lower allostatic load index, and sedentary behaviour is associated with a higher allostatic load index. Physical activity is a modifiable factor related to allostatic load.

Associations between Autonomic and Endocrine Reactivity to Stress in Adolescence: Related to the Development of Anxiety?

Internalizing disorders in adolescence have been associated with disturbances in autonomic and endocrine functioning. Because the prefrontal cortex and the limbic system play a central role in regulating both the autonomic and the endocrine systems, their joint functioning is hypothesized to provide information about the potential development of internalizing symptoms throughout adolescence, notably in the preclinical stage. This hypothesis was tested in a sample of 198 adolescents from the general population. Heart rate variability (HRV) and skin conductance levels (SCLs) were measured before, during, and after a public speaking task. These autonomic parameters were associated with cortisol response to the task in the complete sample as well as in low- and high-anxiety adolescents separately. Self-reported social anxiety, low HRV, and high SCL recovery values were predictive of cortisol response. Importantly, in low-anxiety adolescents, only HRV during the task predicted the cortisol response, whereas, in their highly anxious peers, both HRV and SCL were strongly associated with this response. In the latter finding, age was a prominent factor. Additional analyses supported the idea that the interaction of autonomic and endocrine reactivity is subject to natural development. These findings provide evidence that adolescence might be a period of highly interactive emotional–neurobiological development, particularly with respect to the development of stress management skills.

Naturopathic Management of Acute Pediatric Respiratory Infections: A Modified Delphi Study

Objective: Both the United Nations and the World Health Organization have identified antimicrobial resistance as a significant threat to global health. The Centers for Disease Control and Prevention identified five pediatric respiratory conditions as requiring particular scrutiny in terms of antibiotic stewardship. This study sought to identify strategies used by experienced naturopathic practitioners to treat acute respiratory infections in children. The authors theorize that naturopathic strategies safely fill the gap between watchful waiting and antibiotic prescription, thus reducing the use of antibiotics. Methods: Naturopathic practitioners in Canada, the United States, and Australia with a minimum of 5 years of experience in clinical naturopathic care of children were recruited for a modified Delphi study. A 14-person panel of practitioners was selected to complete a series of four iterative surveys assessing agreement to statements in five domains of knowledge/attitudes, assessment/diagnosis, management, monitoring, and education. Items were deemed to have reached consensus if they reached a predetermined threshold of 70% agreement, or failed to reach a threshold of 40% agreement. Items between these boundaries were modified and retested until either consensus was reached or the four surveys had been completed. Results: Results yielded a large degree of agreement on core naturopathic approaches to the management of acute pediatric respiratory infections, especially lifestyle strategies, including adequate rest and dietary recommendations. The use of vitamins C and D was strongly supported, as were herbs, particularly echinacea and elderberry. Some hydrotherapy and topical applications specific to the individual focus on infection also reached consensus. Results suggested that most respondents, even if they have the authority to prescribe antibiotics, rarely deem it necessary to do so. Conclusion: Findings of this study provide (1) clarity on the role of naturopathic doctors in the management of pediatric health concerns and the stewardship of antibiotics; and (2) initial guidance to less experienced naturopathic practitioners. The findings also identify key priorities for research into the safety and effectiveness of naturopathic interventions to reduce the unnecessary prescribing of antibiotics.

Biological Burden of Adverse Childhood Experiences in Children

OBJECTIVE

This study aimed to examine relationships between adverse childhood experiences (ACEs) and related life events and allostatic load (AL)-"wear and tear" from chronic stress-in a pediatric population.

METHODS

Children were screened with the PEdiatric ACEs and Related Life Event Screener (PEARLS) tool, a 17-item questionnaire capturing experiences of abuse, neglect, household challenges, and related life events. Biological data were available for 207 participants, and AL was operationalized using clinical or empirical cutoff points across 4 physiological systems (i.e., cardiac, metabolic, inflammatory, neurologic). Covariate-adjusted multivariable regression models were used to examine associations between AL with adversity and health.

RESULTS

Children (mean age = 6.5 years, range = 1-11 years) had an average AL score of 1.9 (standard deviation = 1.7), and a U-shaped relationship was observed with child's age. Continuous PEARLS and original ACE scores were not associated with AL. However, children with a reported PEARLS score of 1 to 2 or original ACEs score of 1 to 3 had 1.5 (incidence rate ratio [IRR] = 1.50, 95% confidence interval [CI] = 1.09-2.08) and 1.4 (IRR = 1.41, 95% CI = 1.08-1.84) times greater AL, respectively, compared with participants with none reported. In secondary analyses, caregiver mental illness was associated with higher child AL (adjusted IRR = 1.27, 95% CI = 1.01-1.58). AL was also associated with poorer perceived child general health (adjusted β = -0.87, 95% CI = -1.58 to -0.15) and greater odds of child obesity (adjusted odds ratio = 1.51, 95% CI = 1.23-1.89).

CONCLUSIONS

Measuring AL in a pediatric population requires careful consideration of age. Higher AL was associated with a greater number of reported adversities and worse child health.

Longitudinal associations between allostatic load, pet ownership, and socioeconomic position among U.S. adults aged 50

It is hypothesized that pets provide benefits to human health by buffering the deleterious effects of stress, but varying exposure to chronic stress via social position is rarely considered in these conceptual and empirical models. Allostatic load is an index of biological and physical measures that represents cumulative wear and tear on the body via chronic stress exposure. In this study, we use the 2006-2016 waves of the Health and Retirement Study, a nationally representative, longitudinal panel survey of adults aged 50+ in the United States, to test whether and to what extent pet ownership has an impact on allostatic load, and whether pet ownership moderates the effects of socioeconomic position on allostatic load. Linear mixed effects regression models revealed that pet owners had significantly lower allostatic load scores than those who do not own pets; however, after adjusting for socioeconomic position (i.e., wealth, education, race, ethnicity, gender, marital status), the effect of pet ownership was no longer significant. We estimated a series of models stratified by sociodemographic groups to test moderation effects. Among those who had a high school education, pet owners had lower allostatic load scores, whereas among those who had attended some college, pet owners had higher scores. Among those who were aged 80+, pet owners had higher scores than those who did not own pets. These findings suggest that the magnitude of the effect of pet ownership on allostatic load may not be sufficient to counteract experiences of high chronic stress as experienced by lower-status groups. Supporting the human-animal bond may contribute to improving older adult population health if paired with efforts to address the underlying causes of population health disparities.

Envisioning translational hyperscanning: how applied neuroscience might improve family-centered care

From the very beginning of their life, human beings are immersed in a social and interactive environment that contributes to shaping their social and cognitive development under typical and at-risk conditions. In order to understand human development in its bidirectional relationship with the social environment, we need to develop a 'complexity-sensitive' approach in neuroscience. Recent advances have started to do so with the application of hyperscanning techniques which involve recording adult and child neural activity simultaneously and highlighting the presence of similar patterns of brain activity in the dyad. Numerous studies focused on typically developing children have been published in recent years with the application of this technique to different fields of developmental research. However, hyperscanning techniques could also be extremely beneficial and effective in studying development in atypical and clinical populations. Such application, namely translational hyperscanning, should foster the transition toward a two-brain translational neuroscience. In this paper, we envision how the application of hyperscanning to atypical and clinical child populations can inform family-centered care for children and their parents.

The association between allostatic load and brain: A systematic review

Allostatic load (AL) refers to prolonged dysregulation related to chronic stress that affects brain regions such as the hippocampus, amygdala, and prefrontal cortex (PFC). Higher levels of AL have been associated with poor health outcomes, including psychiatric disorders, cognitive decline, and chronic somatic conditions. However, still little is known about the relationship between AL and the brain, and the mechanisms explaining the damaging effects of stress-related biological dysregulations. Therefore, we aimed to perform a systematic review of studies investigating the association of the AL index with brain structure and functioning in adult populations. PubMed/MEDLINE, CINAHL, Academic Search Complete and Web of Science were searched from their inception until August, 9th 2021. A total of 13 studies were included in the qualitative synthesis. There was a high between-study heterogeneity with respect to the methods used to calculate the AL index and brain parameters. All studies confirmed the associations between a higher AL index and alterations in various brain areas, especially: 1) the hippocampus, white matter volume, gray matter volume, and density in the older adults; 2) the cortex, fornix, hippocampus and choroid plexus in patients with schizophrenia spectrum disorders; and 3) whole-brain white matter tracts, cortical gray matter volume, and cortical thickness in overweight subjects. Overall, the findings of this systematic review imply that an elevated AL index might be associated with various neurostructural and neurofunctional alterations. Some of these associations may appear regardless of clinical or non-clinical populations being investigated (e.g., white matter tracts), whereas others may appear in specific populations (e.g., cortical thinning in overweight/obesity and schizophrenia spectrum disorders). However, additional studies utilizing a consistent approach to calculating the AL index are needed to extend these findings and indicate populations that are most vulnerable to the damaging effects of AL.

Prenatal allostatic load and preterm birth: A systematic review

Objective

Allostatic load refers to cumulative neuroendocrine burden and has been postulated to mediate and moderate physiological and psychological stress-related responses. This may have important implications for the risk of preterm birth. This systematic review examines the evidence on the association between prenatal allostatic load and preterm birth.

Data sources

A comprehensive search of seven electronic databases was conducted from inception to August 23, 2022 to identify all English-language observational and mixed methods studies examining allostatic load and preterm birth with no year or geographic restrictions.

Study eligibility criteria

Studies were included if they measured allostatic load, evaluated as the cumulative effect of any combination of more than one allostatic load biomarker, during pregnancy. Studies must have observed preterm birth, defined as &lt; 37 weeks' gestational age, as a primary or secondary outcome of interest.

Study appraisal and synthesis methods

The Quality In Prognosis Studies tool was used to evaluate risk of bias within included studies. A narrative synthesis was conducted to explore potential associations between allostatic load and preterm birth, and sources of heterogeneity.

Results

Three prospective cohort studies were identified and revealed mixed evidence for an association between allostatic load and preterm birth. One study reported a statistically significant association while the other two studies reported little to no evidence for an association. Heterogeneity in when and how allostatic load was measured, limitations in study design and cohort socio-demographics may have contributed to the mixed evidence.

Conclusions

This review provides insight into key individual-, community-, and study-level characteristics that may influence the association between allostatic load and preterm birth. Knowledge gaps are identified as foci for future research, including heterogeneity in allostatic load biomarkers and allostatic load index algorithms as well as pregnancy-specific considerations for allostatic load measurement. Further investigation of the allostatic load framework in the context of perinatal mental health is needed to advance understandings of maternal, infant, and child health.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020208990, PROSPERO, identifier: CRD42020208990.

Development of the College Student Acute Stress Scale (CSASS)

PURPOSE

The purpose of this study is to develop and validate the College Student Acute Stress Scale, a measure of acute stress specific to college students.

DESIGN AND METHODS

A total sample of 440 young adults from a university in the northeast United States were surveyed across three separate research studies. Exploratory principal component analysis, internal consistency reliability, convergent and divergent validity, and test-retest reliability analyses were performed.

FINDINGS

Evidence of convergent and divergent validity were obtained, and adequate internal consistency and test-retest reliability were identified.

PRACTICE IMPLICATIONS

This study provides evidence for the validity and reliability of a self-report measure of college students' acute stress experiences.

Cost of resilience: Childhood poverty, mental health, and chronic physiological stress

Childhood poverty is associated with elevated internalizing symptoms. Nevertheless, some children exposed to poverty evince remarkable resilience, demonstrating lower than expected levels of psychological distress. However, recent work suggests that coping with adversity can lead to undesirable physical health consequences. Specifically, successful adaptation in the context of early adversity, including socioeconomic disadvantage, appears to be associated with elevated chronic physiological stress and ill health. The current study adds to this emerging literature by examining in a longitudinal context whether low levels of internalizing symptoms in the face of childhood poverty is accompanied by elevated chronic physiological stress (allostatic load) during childhood, as well as over time from childhood to adulthood. Results (n = 341; M=9.2 years, 49 % female; 94 % Caucasian) show that childhood poverty was prospectively associated with higher allostatic load during adolescence, controlling for baseline allostatic load. Furthermore, greater duration of childhood poverty led to steeper, more elevated allostatic load trajectories from childhood to adulthood, for youth with lower levels of internalizing symptoms. Efforts to manage adverse sequelae of early adversity likely yield a complex array of benefits and costs.

The Impact of Chronic Unpredictable Mild Stress-Induced Depression on Spatial, Recognition and Reference Memory Tasks in Mice: Behavioral and Histological Study

Depression-induced cognitive impairment has recently been given more attention in research. However, the relationship between depression and different types of memory is still not clear. Chronic unpredictable mild stress (CUMS) is a commonly used animal model of depression in which animals are exposed to chronic unpredictable environmental and psychological stressors, which mimics daily human life stressors. This study investigated the impact of different durations of CUMS on various types of memory (short- and long-term spatial memory and recognition memory) and investigated CUMS’ impact on the ultrastructural level by histological assessment of the hippocampus and prefrontal cortex. Twenty male C57BL/J6 mice (6 weeks old, 21.8 ± 2 g) were randomly divided into two groups (n = 10): control and CUMS (8 weeks). A series of behavioral tasks were conducted twice at weeks 5–6 (early CUMS) and weeks 7–8 (late CUMS). A tail-suspension test (TST), forced swimming test (FST), elevated zero maze (EZM), elevated plus maze (EPM), open field test (OFT), and sucrose-preference test (SPT) were used to assess anxiety and depressive symptoms. The cognitive function was assessed by the novel object recognition test (NORT; for recognition memory), Y-maze (for short-term spatial memory), and Morris water maze (MWM: for long-term spatial memory) with a probe test (for reference memory). Our data showed that 8 weeks of CUMS increased the anxiety level, reported by a significant increase in anxiety index in both EPM and EZM and a significant decrease in central preference in OFT, and depression was reported by a significant increase in immobility in the TST and FST and sucrose preference in the SPT. Investigating the impact of CUMS on various types of memory, we found that reference memory is the first memory to be affected in early CUMS. In late CUMS, all types of memory were impaired, and this was consistent with the abnormal histological features of the memory-related areas in the brain (hippocampus and prefrontal cortex).

Early experience unpredictability in child development as a model for understanding the impact of the COVID-19 pandemic: A translational neuroscience perspective

Extensive evidence links adverse experiences during childhood to a wide range of negative consequences in biological, socioemotional, and cognitive development. Unpredictability is a core element underlying most forms of early adversity; it has been a focus of developmental research for many years and has been receiving increasing attention recently. In this article, we propose a conceptual model to describe how unpredictable and adverse early experiences affect children's neurobiological, behavioral, and psychological development in the context of the COVID-19 pandemic. We first highlight the critical role of unpredictability in child development by reviewing existing conceptual models of early adversity as they relate to subsequent development across the lifespan. Then, we employ a translational neuroscience framework to summarize the current animal- and human-based evidence on the neurobiological alterations induced by early experience unpredictability. We further argue that the COVID-19 pandemic serves as a global "natural experiment" that provides rare insight to the investigation of the negative developmental consequences of widespread, clustered, and unpredictable adverse events among children. We discuss how the pandemic helps advance the science of unpredictable early adverse experiences. As unpredictability research continues to grow, we highlight several directions for future studies and implications for policymaking and intervention practices.

Integrating dynamic and developmental time scales: Emotion-specific autonomic coordination predicts baseline functioning over time

Autonomic nervous system activity flexibly shifts and modulates behavior at multiple time scales, with some work suggesting that patterns of short-term reactivity contribute to long-term developmental change. However, previous work has largely considered sympathetic and parasympathetic systems independently, even though both systems contribute dynamically to the regulation of physiological arousal. Using physiological data obtained from 313 children in kindergarten, 1st, and 2nd grade we examined whether within-person autonomic coordination during an emotion-inducing film task in kindergarten was associated with developmental change in resting autonomic activity. On average, these kindergarteners exhibited reciprocal coordination during the approach-oriented emotion (angry, happy) condition and a lack of coordination during the avoidance-oriented emotion (fear, sad) condition. Alignment with these patterns was associated with more typical autonomic development, specifically an increase in resting respiratory sinus arrhythmia (RSA) and a decrease in resting skin conductance (SCR) from kindergarten to 2nd grade; while lack of coordination during the approach condition was associated with a relatively delayed increase in resting RSA and a steeper decline in SCR, and reciprocal coordination during the avoidance condition was associated with a lack of RSA increase. Findings highlight the need for additional consideration of how moment-to-moment dynamics of autonomic coordination influence longer-term development, and suggest that early patterns of atypical arousal may portend dysregulation of developing physiological systems.

The contribution of racism-related stress and adversity to disparities in birth outcomes: evidence and research recommendations

Currently, racial and ethnic differences in adverse birth outcomes and infant mortality are some of the largest and most persistent health disparities in the United States. This narrative review article synthesizes existing literature to present a conceptual model of how racism-related stress and adversity are critical determinants of such disparities. We describe how historical and ongoing racism has created conditions wherein women of color are disproportionately exposed to chronic, multilayered stress and adversity and how the biological consequences of exposure to these stressors confers risk for adverse birth outcomes. Next, we identify important priorities and considerations for future research, including the heterogeneity of racism-related stressors, biomarkers and mechanisms, chronicity and sensitive periods of exposure, developmental programming of lifespan health, resilience, and community-engaged research methodologies.

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Historical and ongoing racism has created conditions wherein women of color are disproportionately exposed to stress and adversity.

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The consequences of exposure to racism-related stress and adversity can confer risk for health conditions implicated in adverse birth outcomes and alter maternal physiology associated with fetal development and timing of parturition.

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Conjointly studying racism-related stress, biologic profiles, and birth outcomes is a priority for future research.

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It is important to identify factors that mitigate the impact of racism-related stress and adversity on birth outcomes.