Delayed maturation in brain electrical activity partially explains the association between early environmental deprivation and symptoms of attention-deficit/hyperactivity disorder

Dimensions of early life adversity are differentially associated with patterns of delayed and accelerated brain maturation

BACKGROUND

Different types of early-life adversity have been associated with children's brain structure and function. However, understanding the disparate influence of distinct adversity exposures on the developing brain remains a major challenge.

METHODS

This study investigates the neural correlates of 10 robust dimensions of early-life adversity identified through exploratory factor analysis in a large community sample of youth from the Adolescent Brain Cognitive Development (ABCD) Study. Brain age models were trained, validated, and tested separately on T1-weighted (T1; N = 9524), diffusion tensor (DTI; N = 8834), and resting-state functional (rs-fMRI; N = 8233) magnetic resonance imaging (MRI) data from two time points (mean age = 10.7 years, SD = 1.2, range = 8.9-13.8 years).

RESULTS

Bayesian multilevel modelling supported distinct associations between different types of early-life adversity exposures and younger- and older-looking brains. Dimensions generally related to emotional neglect, such as lack of primary and secondary caregiver support, and lack of caregiver supervision, were associated with lower brain age gaps (BAGs), i.e., younger-looking brains. In contrast, dimensions generally related to caregiver psychopathology, trauma exposure, family aggression, substance use and separation from biological parent, and socio-economic disadvantage and neighbourhood safety were associated with higher BAGs, i.e., older-looking brains.

CONCLUSIONS

The findings suggest that dimensions of early-life adversity are differentially associated with distinct neurodevelopmental patterns, indicative of dimension-specific delayed and accelerated brain maturation.

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

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

Theta activity and cognitive functioning: Integrating evidence from resting-state and task-related developmental electroencephalography (EEG) research

The theta band is one of the most prominent frequency bands in the electroencephalography (EEG) power spectrum and presents an interesting paradox: while elevated theta power during resting state is linked to lower cognitive abilities in children and adolescents, increased theta power during cognitive tasks is associated with higher cognitive performance. Why does theta power, measured during resting state versus cognitive tasks, show differential correlations with cognitive functioning? This review provides an integrated account of the functional correlates of theta across different contexts. We first present evidence that higher theta power during resting state is correlated with lower executive functioning, attentional abilities, language skills, and IQ. Next, we review research showing that theta power increases during memory, attention, and cognitive control, and that higher theta power during these processes is correlated with better performance. Finally, we discuss potential explanations for the differential correlations between resting/task-related theta and cognitive functioning, and offer suggestions for future research in this area.

Association of Neighborhood Opportunity with Infant Brain Activity and Cognitive Development

BACKGROUND AND OBJECTIVES

Neighborhood socioeconomic disadvantage is associated with lower neurocognitive scores and differences in brain structure among school-age children. Associations between positive neighborhood characteristics, infant brain activity, and cognitive development are underexplored. We examined direct and indirect associations between neighborhood opportunity, brain activity, and cognitive development.

METHODS

This longitudinal cohort study included infants from 2 primary care clinics in Boston and Los Angeles. Using a sample of 65 infants, we estimated path models to examine associations between neighborhood opportunity (measured by the Child Opportunity Index), infant electroencephalography (EEG) at 6 months, and infant cognitive development (measured using the Mullen Scales of Early Learning) at 12 months. A mediation model tested whether EEG power explained associations between neighborhood opportunity and infant cognition.

RESULTS

Neighborhood opportunity positively predicted infant absolute EEG power across multiple frequency bands: low ( b = 0.12, 95% CI 0.01-0.24, p = 0.04, = 0.21); high ( b = 0.11, 95% CI 0.01-0.21, p = 0.03, = 0.23); ( b = 0.10, 95% CI 0.00-0.19, p = 0.04, = 0.20); and ( b = 0.12, 95% CI 0.02-0.22, p = 0.02, = 0.24). The results remained statistically significant after applying a Benjamini-Hochberg false discovery rate of 0.10 to adjust for multiple comparisons. No significant associations emerged between neighborhood opportunity, relative EEG power, and infant cognition. Mediation was not significant.

CONCLUSION

Neighborhood opportunity is positively associated with some forms of infant brain activity, suggesting that positive neighborhood characteristics may play a salient role in early development.

Linking caregiving quality during infancy to brain activity in early childhood and later executive function

There is no relationship more vital than the one a child shares with their primary caregivers early in development. Yet many children worldwide are raised in settings that lack the warmth, connection, and stimulation provided by a responsive primary caregiver. In this study, we used data from the Bucharest Early Intervention Project (BEIP), a longitudinal study of institutionally-reared and family-reared children, to test how caregiving quality during infancy is associated with average EEG power over the first 3.5 years of life in alpha, beta, and theta frequency bands, and associations with later executive function (EF) at age 8 years. The sample comprised 189 children (129 institutionally-reared; 60 family-reared) who contributed data on observed caregiving quality during infancy (baseline; average age of 22 months), resting EEG power at baseline, 30, and 42 months, and performance-based data on a series of EF tasks at 8 years. Using Bayesian estimation, observed caregiving quality at baseline was marginally linked with higher average alpha and beta power, and lower theta power, from baseline to 42 months. In turn, higher average beta power and lower average theta power were marginally associated with higher EF at 8 years. In indirect effects models, higher caregiving quality at baseline was associated with higher EF at 8 years, with a marginal indirect effect through average theta power from baseline to 42 months. Variation in the quality of the early caregiving environment may be associated with later executive function, which is partially underpinned by individual differences in brain activity during early childhood. RESEARCH HIGHLIGHTS: Examined associations between caregiving quality during infancy, brain activity during early childhood, and executive function during mid-childhood in sample of never-institutionalized and institutionally-reared children. Significant associations between higher quality caregiving during infancy and higher executive function during middle childhood. Marginal associations between caregiving quality during infancy and brain activity during early childhood. Marginal associations between brain activity during early childhood and executive function during mid-childhood.

The Necessity of Taking Culture and Context into Account When Studying the Relationship between Socioeconomic Status and Brain Development

Decades of research has revealed a relationship between childhood socioeconomic status (SES) and brain development at the structural and functional levels. Of particular note is the distinction between income and maternal education, two highly correlated factors which seem to influence brain development through distinct pathways. Specifically, while a families' income-to-needs ratio is linked with physiological stress and household chaos, caregiver education influences the day-to-day language environment a child is exposed to. Variability in either one of these environmental experiences is related to subsequent brain development. While this work has the potential to inform public policies in a way that benefits children, it can also oversimplify complex factors, unjustly blame low-SES parents, and perpetuate a harmful deficit perspective. To counteract these shortcomings, researchers must consider sociodemographic differences in the broader cultural context that underlie SES-based differences in brain development. This review aims to address these issues by (a) identifying how sociodemographic mechanisms associated with SES influence the day-to-day experiences of children, in turn, impacting brain development, while (b) considering the broader cultural contexts that may differentially impact this relationship.

Stress as a mediator of brain alterations in attention-deficit hyperactivity disorder: A systematic review

OBJECTIVE

Stress is a known risk factor for numerous psychopathologies, whereas evidence is lacking regarding the specific consequences of stress on the neural basis of attention-deficit hyperactivity disorder (ADHD). A systematic literature review was thus conducted to clarify the role of stress in the association between the resulting alterations of brain structure, connectivity, and function in ADHD.

METHODS

The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under identifier CRD42023379809. A systematic search of the PubMed and CINAHL databases was conducted for articles published prior to December 22nd, 2022. Retrieved literature was screened in Rayyan and data extraction was performed with respect to neuroimaging, stress exposure, and ADHD outcomes. The Quality in Prognosis Studies (QUIPS) tool was adapted based on the Conducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology (COSMOS-E) guidance article to assess risk of bias and quality of studies. Strength of the evidence was assessed under the guidance of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

Screening 25,026 non-duplicate articles yielded 20 eligible studies for inclusion. Exposure to early life trauma, institutionalization, prenatal smoking or alcohol consumption, air pollution, low socioeconomic status, or low birth weight were associated with alterations in brain structure, function, and connectivity in ADHD. However, most studies did not provide strong evidence due to small sample sizes and lack of statistical approaches to determine a direct mediation of the association between stress and ADHD by neural outcomes.

CONCLUSION

This systematic review was the first to summarize evidence of structural and functional stress-associated alterations in the brain, which were found to be directly and indirectly associated with ADHD outcomes. Overall, stress requires consideration as a significant determinant of neurodevelopmental outcomes in ADHD. However, extensive further research is warranted due to little available evidence and the difficulty of obtaining clear results. In light of such a complex research question, in order to confirm findings, provide further evidence, and establish causality systematic longitudinal studies would be required. Investigating the topic may provide invaluable information when it comes to tailoring prevention and treatment strategies in ADHD, and should be pursued in order to integrate the factor of stress into a more comprehensive understanding of ADHD.

Do housing-induced changes in brain activity cause stereotypic behaviours in laboratory mice?

Abnormal repetitive stereotypic behaviours (SBs) (e.g. pacing, body-rocking) are common in animals with poor welfare (e.g. socially isolated/in barren housing). But how (or even whether) poor housing alters animals' brains to induce SBs remains uncertain. To date, there is little evidence for environmental effects on the brain that also correlate with individual SB performance. Using female mice from two strains (SB-prone DBA/2s; SB-resistant C57/BL/6s), displaying two forms of SB (route-tracing; bar-mouthing), we investigated how housing (conventional laboratory conditions vs. well-resourced 'enriched' cages) affects long-term neuronal activity as assessed via cytochrome oxidase histochemistry in 13 regions of interest (across cortex, striatum, basal ganglia and thalamus). Conventional housing reduced activity in the cortex and striatum. However, DBA mice had no cortical or striatal differences from C57 mice (just greater basal ganglia output activity, independent of housing). Neural correlates for individual levels of bar-mouthing (positive correlations in the substantia nigra and thalamus) were also independent of housing; while route-tracing levels had no clear neural correlates at all. Thus conventional laboratory housing can suppress cortico-striatal activity, but such changes are unrelated to SB (since not mirrored by congruent individual and strain differences). Furthermore, the neural correlates of SB at individual and strain levels seem to reflect underlying predispositions, not housing-mediated changes. To aid further work, hypothesis-generating model fit analyses highlighted this unexplained housing effect, and also suggested several regions of interest across cortex, striatum, thalamus and substantia nigra for future investigation (ideally with improved power to reduce risks of Type II error).

Telomere Erosion and Depressive Symptoms Across Development Following Institutional Care

OBJECTIVE

A large literature has identified exposure to early caregiving adversities as a potent risk for developing affective psychopathology, with depression, in particular, increasing across childhood into adolescence. Evidence suggests telomere erosion, a marker of biological aging, may underlie associations between adverse early-life experiences and later depressive behavior; yet, little is understood about this association during development.

METHOD

The current accelerated longitudinal study examined concurrent telomere length and depressive symptoms concurrently, 2 and 4 years later, from the preschool period through adolescence among children exposed (n =116) and not exposed (n = 242) to early previous institutional (PI) care.

RESULTS

PI care was associated with shorter telomeres on average and with quadratic age-related growth in depressive symptoms, indicating a steeper association between PI care and depressive symptoms in younger age groups that leveled off in adolescence. Contrary to studies in adult samples, telomere length was not associated with depressive symptoms, and it did not predict future symptoms.

CONCLUSION

These findings indicate that early caregiving disruptions increase the risk for both accelerated biological aging and depressive symptoms, although these variables did not correlate with each other during this age range.

Childhood stress, gender, and cognitive control: Midline theta power

The emergence of psychiatric symptoms is a common consequence of childhood stress exposure. However, there are a dearth of reliable clinical hallmarks or physiological biomarkers to predict post-trauma symptom emergence. The objective of this study was to examine if childhood stressors and stress-related symptoms are associated with altered midline theta power (MTP) during cognitive control demands, and how these associations interact with gender and early adversity. N = 53 children (ages 9-13 years old) from a longitudinal study of children maltreated during early childhood and non-maltreated children participated in this study. EEG recorded neural activity during a Zoo-Themed Go/No-Go task. Stress-related symptoms, recent stressful events, and other adversity experiences were identified. MTP was analyzed with clinical variables in a series of follow-up analyses. The number of stressors in the past six months was negatively correlated with MTP in those with low preschool adversity, but not in those with high preschool adversity. MTP was higher in girls than in boys, and the associations of MTP with stressors and symptoms were moderated by gender. MTP was negatively associated with stressors in the past six months in girls, while in boys, MTP was associated with stress-related symptoms. Childhood stressful events were associated with reduced MTP during cognitive control demands, and this was finding was moderated by gender and early life adversity. These preliminary findings suggest that boys and girls may process stressful experiences in distinct ways, and preschool adversity may potentially blunt the interaction between current stress and neural dynamics. However, ongoing investigation is needed.

Is there evidence of a causal link between childhood maltreatment and attention deficit/hyperactivity disorder? A systematic review of prospective longitudinal studies using the Bradford-Hill criteria

Background

Studies report an elevated risk of maltreatment in children with attention deficit/hyperactivity disorder (ADHD), and elevated levels of ADHD in people who suffered childhood maltreatment (CM). However, the direction(s) of causality between CM and ADHD remain unclear-does ADHD create a context for CM, does CM cause ADHD, or both?

Objective

This study systematically reviews and qualitatively synthesizes the research evidence relating to this question using Bradford-Hill criteria for establishing causality-strength, temporality, dose-response and plausibility.

Methods

We conducted a systematic review, following PRISMA guidelines, of prospective longitudinal studies examining both CM and ADHD. We then used Bradford-Hill criteria to assess the quality of evidence for a causal link between CM and ADHD.

Results

All 11 included studies demonstrated an association between CM and ADHD. Seven included evidence for temporality: five suggesting that CM precedes ADHD in the lifespan; two suggesting ADHD precedes CM. Four studies demonstrated a dose response relationship in which greater CM exposure was associated with elevated risk of ADHD. Studies presented a range of plausible mechanisms, including CM causing ADHD through biological programming, versus ADHD causing CM through parental stress.

Conclusions

The high quality prospective longitudinal studies reviewed confirm the association between ADHD and CM, but present conflicting evidence about the direction of causality and mechanisms underpinning this association. To better understand the complex interplay between CM and ADHD, more studies using new research designs will be required that can partition effects by type of CM and account for bidirectional effects and other complexities.

Associations between maternal stress and infant resting brain activity among families residing in poverty in the U.S

Growing evidence suggests that maternal experiences of stress shape children's functional brain activity in the first years of life. Individuals living in poverty are more likely to experience stress from a variety of sources. However, it is unclear how stress is related to resting brain activity among children born into poverty. The present study examines whether infants born into households experiencing poverty show differences in brain activity associated with maternal reports of experiencing stress. The analytic sample comprised 247 mother-infant dyads who completed maternal questionnaires characterizing stress, and for whom recordings of infant resting brain activity were obtained at 1 year of age (M=12.93 months, SD=1.66; 50% female). Mothers (40% Black, non-Hispanic, 40% Hispanic, 12% White, non-Hispanic) who reported higher stress had infants who showed more resting brain activity in the lower end of the frequency spectrum (relative theta power) and less resting brain activity in the middle range of the frequency spectrum (relative alpha power). While statistically detectable at the whole-brain level, follow-up exploratory analyses revealed that these effects were most apparent in electrodes over frontal and parietal regions of the brain. These findings held after adjusting for a variety of potentially confounding variables. Altogether, the present study suggests that, among families experiencing low economic resources, maternal reports of stress are associated with differences in patterns of infant resting brain activity during the first year of life.

A systematic review of interventions to ameliorate the impact of adversity on brain development

Adversity, including abuse, neglect, and poverty, impacts child brain development. However, the developing brain is highly plastic, and some of the impacts of childhood adversity may be mitigated by psychosocial interventions. The purpose of this review is to synthesize literature on neural outcomes of childhood interventions among individuals exposed to adversity. A systematic literature search identified 36 reports of 13 interventions. Overall, these studies provide evidence for experience-dependent plasticity in the developing brain. We synthesize studies in light of three themes. First, there was mixed evidence for a benefit of a younger age at intervention. Second, interventions tended to accelerate functional brain development, but the impact of interventions on the pace of structural brain development was less clear. Third, individual differences in intervention response were difficult to predict, in part due to small samples. However, there was significant variability in intervention type and timing, neuroimaging outcomes, and follow-up timing. Together, the studies reviewed here hold promise for the role of psychosocial interventions in ameliorating the neurodevelopmental consequences of childhood adversity.

Resting brain activity in early childhood predicts IQ at 18 years

Resting brain activity has been widely used as an index of brain development in neuroscience and clinical research. However, it remains unclear whether early differences in resting brain activity have meaningful implications for predicting long-term cognitive outcomes. Using data from the Bucharest Early Intervention Project (Zeanah et al., 2003), we examined the impact of institutional rearing and the consequences of early foster care intervention on 18-year IQ. We found that higher resting theta electroencephalogram (EEG) power, reflecting atypical neurodevelopment, across three assessments from 22 to 42 months predicted lower full-scale IQ at 18 years, providing the first evidence that brain activity in early childhood predicts cognitive outcomes into adulthood. In addition, both institutional rearing and later (vs. earlier) foster care intervention predicted higher resting theta power in early childhood, which in turn predicted lower IQ at 18 years. These findings demonstrate that experientially-induced changes in brain activity early in life have profound impact on long-term cognitive development, highlighting the importance of early intervention for promoting healthy development among children living in disadvantaged environments.

Social isolation and the brain: effects and mechanisms

An obvious consequence of the coronavirus disease (COVID-19) pandemic is the worldwide reduction in social interaction, which is associated with many adverse effects on health in humans from babies to adults. Although social development under normal or isolated environments has been studied since the 1940s, the mechanism underlying social isolation (SI)-induced brain dysfunction remains poorly understood, possibly due to the complexity of SI in humans and translational gaps in findings from animal models. Herein, we present a systematic review that focused on brain changes at the molecular, cellular, structural and functional levels induced by SI at different ages and in different animal models. SI studies in humans and animal models revealed common socioemotional and cognitive deficits caused by SI in early life and an increased occurrence of depression and anxiety induced by SI during later stages of life. Altered neurotransmission and neural circuitry as well as abnormal development and function of glial cells in specific brain regions may contribute to the abnormal emotions and behaviors induced by SI. We highlight distinct alterations in oligodendrocyte progenitor cell differentiation and oligodendrocyte maturation caused by SI in early life and later stages of life, respectively, which may affect neural circuit formation and function and result in diverse brain dysfunctions. To further bridge animal and human SI studies, we propose alternative animal models with brain structures and complex social behaviors similar to those of humans.

Perinatal and early childhood biomarkers of psychosocial stress and adverse experiences

The human brain develops through a complex interplay of genetic and environmental influences. During critical periods of development, experiences shape brain architecture, often with long-lasting effects. If experiences are adverse, the effects may include the risk of mental and physical disease, whereas positive environments may increase the likelihood of healthy outcomes. Understanding how psychosocial stress and adverse experiences are embedded in biological systems and how we can identify markers of risk may lead to discovering new approaches to improve patient care and outcomes. Biomarkers can be used to identify specific intervention targets and at-risk children early when physiological system malleability increases the likelihood of intervention success. However, identifying reliable biomarkers has been challenging, particularly in the perinatal period and the first years of life, including in preterm infants. This review explores the landscape of psychosocial stress and adverse experience biomarkers. We highlight potential benefits and challenges of identifying risk clinically and different sub-signatures of stress, and in their ability to inform targeted interventions. Finally, we propose that the combination of preterm birth and adversity amplifies the risk for abnormal development and calls for a focus on this group of infants within the field of psychosocial stress and adverse experience biomarkers. IMPACT: Reviews the landscape of biomarkers of psychosocial stress and adverse experiences in the perinatal period and early childhood and highlights the potential benefits and challenges of their clinical utility in identifying risk status in children, and in developing targeted interventions. Explores associations between psychosocial stress and adverse experiences in childhood with prematurity and identifies potential areas of assessment and intervention to improve outcomes in this at-risk group.

Timing of adoption is associated with electrophysiological brain activity and externalizing problems among children adopted internationally

This study investigated middle childhood resting electroencephalography (EEG) and behavioral adjustment in 35 internationally adopted children removed from early caregiving adversity between 6 and 29 months of age. Older age of adoption was associated with more immature or atypical profiles of middle childhood cortical function, based on higher relative theta power (4-6 Hz), lower relative alpha power (7-12 Hz), lower peak alpha frequency, and lower absolute beta (13-20 Hz) and gamma (21-50 Hz) power. More immature or atypical EEG spectral power indirectly linked older age of adoption with increased risk for externalizing problems in middle childhood. The findings add to existing evidence linking duration of early adverse exposures with lasting effects on brain function and behavioral regulation even years after living in a stable adoptive family setting. Findings underscore the need to minimize and prevent children's exposures to early caregiving adversity, especially in the first years of life. They call for innovative interventions to support neurotypical development in internationally adopted children at elevated risk.

Consequences of Inadequate Caregiving for Children's Attachment, Neurobiological Development, and Adaptive Functioning

Given that human infants are almost fully reliant on caregivers for survival, the presence of parents who provide sensitive, responsive care support infants and young children in developing the foundation for optimal biological functioning. Conversely, when parents are unavailable or insensitive, there are consequences for infants' and children's attachment and neurobiological development. In this paper, we describe effects of inadequate parenting on children's neurobiological and behavioral development, with a focus on developing capacities for executive functioning, emotion regulation, and other important cognitive-affective processes. Most prior research has examined correlational associations among these constructs. Given that interventions tested through randomized clinical trials allow for causal inferences, we review longitudinal intervention effects on children's biobehavioral and cognitive-affective outcomes. In particular, we provide an overview of the Bucharest Early Intervention Project, a study in which children were randomized to continue in orphanage care (typically the most extreme condition of privation) or were placed into the homes of trained, supported foster parents. We also discuss findings regarding Attachment and Biobehavioral Catch-up, an intervention enhancing sensitivity among high-risk parents. We conclude by suggesting future directions for research in this area.

Maternal Stress and Early Neurodevelopment: Exploring the Protective Role of Maternal Growth Mindset

OBJECTIVE

The purpose of this study was to test associations between maternal stress, maternal mindset, and infant neurodevelopment at 12 months of age. Specifically, we sought to examine the extent to which maternal growth mindsets may serve to attenuate the negative associations between maternal stress and infants' neurodevelopment.

METHODS

The current exploratory study leverages data from a longitudinal cohort study following mother-infant dyads. Maternal-perceived stress, maternal mindset, and infant electroencephalography (EEG) recordings were collected when infants were 12 months of age. The final analytic sample included 33 dyads.

RESULTS

Results revealed no statistically significant main effects of maternal stress or maternal mindset for any of the infant EEG frequency band outcomes. After including interactions between maternal stress and mindset, statistically significant positive interactions were detected for all EEG frequency bands. Simple slope tests revealed significant negative associations between maternal stress and each of the 6 EEG frequency bands for mothers with more fixed-oriented mindsets. Associations between maternal stress and infant EEG outcomes for mothers with more growth-oriented mindsets did not differ from 0.

CONCLUSION

These findings suggest that infants raised by mothers with growth mindsets may be protected against the neurodevelopmental consequences of higher maternal stress.

The impact of a poverty reduction intervention on infant brain activity

This study demonstrates the causal impact of a poverty reduction intervention on early childhood brain activity. Data from the Baby’s First Years study, a randomized control trial, show that a predictable, monthly unconditional cash transfer given to low-income families may have a causal impact on infant brain activity. In the context of greater economic resources, children’s experiences changed, and their brain activity adapted to those experiences. The resultant brain activity patterns have been shown to be associated with the development of subsequent cognitive skills.

Early childhood poverty is a risk factor for lower school achievement, reduced earnings, and poorer health, and has been associated with differences in brain structure and function. Whether poverty causes differences in neurodevelopment, or is merely associated with factors that cause such differences, remains unclear. Here, we report estimates of the causal impact of a poverty reduction intervention on brain activity in the first year of life. We draw data from a subsample of the Baby’s First Years study, which recruited 1,000 diverse low-income mother–infant dyads. Shortly after giving birth, mothers were randomized to receive either a large or nominal monthly unconditional cash gift. Infant brain activity was assessed at approximately 1 y of age in the child’s home, using resting electroencephalography (EEG; n = 435). We hypothesized that infants in the high-cash gift group would have greater EEG power in the mid- to high-frequency bands and reduced power in a low-frequency band compared with infants in the low-cash gift group. Indeed, infants in the high-cash gift group showed more power in high-frequency bands. Effect sizes were similar in magnitude to many scalable education interventions, although the significance of estimates varied with the analytic specification. In sum, using a rigorous randomized design, we provide evidence that giving monthly unconditional cash transfers to mothers experiencing poverty in the first year of their children’s lives may change infant brain activity. Such changes reflect neuroplasticity and environmental adaptation and display a pattern that has been associated with the development of subsequent cognitive skills.

Systematic Review and Meta-analysis: The Science of Early-Life Precursors and Interventions for Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To evaluate which early neurocognitive and behavioral precursors are associated with the development of attention-deficit/hyperactivity disorder (ADHD) and whether these are currently targeted in early interventions.

METHOD

We conducted 2 systematic reviews and meta-analyses of empirical studies to examine the following: (1) early-life (0-5 years) neurocognitive and behavioral precursors associated with familial likelihood for ADHD, an early ADHD diagnosis/elevated ADHD symptoms, and/or the presence of later-childhood ADHD; and (2) interventions delivered to children aged 0 to 5 years targeting the identified precursors or measuring these as outcomes. Standardized mean differences (Hedges' g) and pre-post-treatment change scores (SMD) were computed.

RESULTS

A total of 149 studies (165,095 participants) investigating 8 neurocognitive and behavioral domains met inclusion criteria for part 1. Multi-level random-effects meta-analyses on 136 studies revealed significant associations between ADHD and poorer cognitive (g = -0.46 [95% CIs: -0.59, -0.33]), motor (g = -0.35 [CIs: -0.48, -0.21]) and language (g = -0.43 [CIs: -0.66, -0.19]) development, social (g = 0.23 [CIs: 0.03, 0.43]) and emotional (g = 0.46 [CIs: 0.33, 0.58]) difficulties, early regulatory (g = 0.30 [CIs: 0.18, 0.43]) and sleep (g = 0.29 [CIs: 0.14, 0.44]) problems, sensory atypicalities (g = 0.52 [CIs: 0.16, 0.88]), elevated activity levels (g = 0.54 [CIs: 0.37, 0.72]), and executive function difficulties (g = 0.34 [CIs: 0.05, 0.64] to -0.87 [CIs: -1.35, -0.40]). A total of 32 trials (28 randomized, 4 nonrandomized, 3,848 participants) testing early interventions that targeted the identified precursors met inclusion criteria for part 2. Multi-level random-effects meta-analyses on 22 studies revealed significant intervention-related improvements in ADHD symptoms (SMD = 0.43 [CIs: 0.22, 0.64]) and working memory (SMD = 0.37 [CIs: 0.06, 0.69]).

CONCLUSION

Children aged 0 to 5 years with current or later-emerging ADHD are likely to experience difficulties in multiple neurocognitive/behavioral functions. Early interventions show some effectiveness in reducing ADHD symptoms, but their effects on neurocognitive/behavioral difficulties require further study.

The role of sociodemographic and psychosocial variables in early childhood development: A secondary data analysis of the 2014 and 2019 Multiple Indicator Cluster Surveys in the Dominican Republic

The association between sociodemographic factors-poverty, lack of maternal schooling, being male at birth-, childhood developmental delay, and poor educational outcomes has been established in the Dominican Republic (DR). However, family moderating factors present or introduced to buffer sociodemographic factors effects on early childhood development (ECD) are still unknown. We conducted a secondary analysis of the DR's 2014 and 2019 Multiple Indicator Cluster Surveys. We had four study aims: 1) confirm the relationship between socioeconomic position (SP), parenting practices, and ECD; 2) determine if a sociodemographic model predicted ECD; 3) determine if a psychosocial model (family childrearing practices, discipline, and early childhood stimulation) predicted ECD above and beyond the sociodemographic model; 4) explore mothers' beliefs about physical punishment and its relationship with ECD and psychosocial variables. We found that both models predicted ECD significantly, but the psychosocial model explained more variance than the sociodemographic model (6.3% in 2014 and 4.4% in 2019). The most relevant sociodemographic predictors were SP (explaining 21.6% of ECD variance in 2014 and 18.6% in 2019) and mother's education (explaining 13.9% in 2014 and 14.1% in 2019). The most salient ECD psychosocial predictors were: negative discipline, number of children's books at home, stimulating activities at home, and attendance to an early childhood education program. The predicting weights of the independent variables were similar for both years. These results have multiple implications for social programs that aim to improve children's potential in contexts of poverty. Although the results show a protective effect of psychosocial factors, sustainable and large-scale interventions should not be limited to just buffering effects, but to solve the underlying problem, which is that poverty prevents children from reaching their developmental potential and exposes them to life-long greater risk for chronic disease. Addressing delays early in life can therefore contribute to achieving health equity.

Brain Structural and Functional Connectivity: A Review of Combined Works of Diffusion Magnetic Resonance Imaging and Electro-Encephalography

Implications of structural connections within and between brain regions for their functional counterpart are timely points of discussion. White matter microstructural organization and functional activity can be assessed in unison. At first glance, however, the corresponding findings appear variable, both in the healthy brain and in numerous neuro-pathologies. To identify consistent associations between structural and functional connectivity and possible impacts for the clinic, we reviewed the literature of combined recordings of electro-encephalography (EEG) and diffusion-based magnetic resonance imaging (MRI). It appears that the strength of event-related EEG activity increases with increased integrity of structural connectivity, while latency drops. This agrees with a simple mechanistic perspective: the nature of microstructural white matter influences the transfer of activity. The EEG, however, is often assessed for its spectral content. Spectral power shows associations with structural connectivity that can be negative or positive often dependent on the frequencies under study. Functional connectivity shows even more variations, which are difficult to rank. This might be caused by the diversity of paradigms being investigated, from sleep and resting state to cognitive and motor tasks, from healthy participants to patients. More challenging, though, is the potential dependency of findings on the kind of analysis applied. While this does not diminish the principal capacity of EEG and diffusion-based MRI co-registration, it highlights the urgency to standardize especially EEG analysis.

Deriving within-person estimates of delta-beta coupling: A novel measure for identifying individual differences in emotion and neural function in childhood

Delta-beta coupling is increasingly used to understand early emotional development. However, little is known about the development of the coupling, limiting its utility for identifying normative or aberrant functioning. We used a prospective longitudinal sample (N = 122) to compare measures of within-person and between-person coupling between ages 3 and 5, track the developmental trajectory of coupling, identify individual differences in patterns of development, and explore emotion-related predictors and outcomes of discrete developmental patterns. Within-person measures, limited in overall utility, were most useful when (1) statistical approaches produced more homogenous groups within the overall sample (extreme groups or latent classes) or (2) the full developmental course was considered. We found two trajectories of change in frontal coupling and three trajectories of change in parietal coupling. Coupling trajectories were predicted by observed fear and approach/avoidance at age 3. In addition, high levels of frontal coupling at age 3 that declined and then levelled out through age 5 were associated with lower levels of internalizing by age 5. This work provides a foundation for understanding normative change in delta-beta coupling across the preschool years and useful insight for the use of this metric in future work.

A randomized controlled trial testing the efficacy of a Nurse Home Visiting Program for Pregnant Adolescents

To test the efficacy of a nurse home visiting program (HVP) on child development, maternal and environmental outcomes in the first years of life. We conducted a randomized controlled trial to test the efficacy of Primeiros Laços, a nurse HVP for adolescent mothers living in a poor urban area of São Paulo, Brazil. Eighty adolescent mothers were included and randomized to receive either Primeiros Laços (intervention group, n = 40) or healthcare as usual (control group, n = 40). Primeiros Laços is a home visiting intervention delivered by trained nurses that starts during the first 16 weeks of pregnancy and continues to the child's age of 24 months. Participants were assessed by blind interviewers at 8-16 weeks of pregnancy (baseline), 30 weeks of pregnancy, and 3, 6, 12, and 24 months of child's age. We assessed oscillatory power in the mid-range alpha frequency via electroencephalography when the children were aged 6 months. Child development was measured by the Bayley Scales of Infant Development Third Edition (BSID-III). Weight and length were measured by trained professionals and anthropometric indexes were calculated. The home environment and maternal interaction with the child was measured by the Home Observation and Measurement of the Environment. Generalized estimating equation models were used to examine intervention effects on the trajectories of outcomes. Standardized effect sizes (Cohen's d) were calculated using marginal means from endpoint assessments of all outcomes. The trial was registered at clinicaltrial.gov: NCT02807818. Our analyses showed significant positive effects of the intervention on child expressive language development (coefficient = 0.89, 95% CI [0.18, 1.61], p = 0.014), maternal emotional/verbal responsivity (coefficient = 0.97, 95% CI [0.37, 1.58], p = 0.002), and opportunities for variety in daily stimulation (coefficient = 0.37, 95% CI [0.09, 0.66], p = 0.009). Standardized effect sizes of the intervention were small to moderate. Primeiros Laços is a promising intervention to promote child development and to improve the home environment of low-income adolescent mothers. However, considering the limitations of our study, future studies should be conducted to assess Primeiros Laços potential to benefit this population.Clinical Trial Registration: The study was registered at clinicaltrial.gov (Registration date: 21/06/2016 and Registration number: NCT02807818).

Associations Between Maternal Stress, Early Language Behaviors, and Infant Electroencephalography During the First Year of Life

Associations have been observed between socioeconomic status (SES) and language outcomes from early childhood, but individual variability is high. Exposure to high levels of stress, often associated with low-SES status, might influence how parents and infants interact within the early language environment. Differences in these early language behaviors, and in early neurodevelopment, might underlie SES-based differences in language that emerge later on. Analysis of natural language samples from a predominantly low-/mid-income sample of mother-infant dyads, obtained using the Language Environment Analysis (LENA) system, found that maternal reports of exposure to stressful life events, and perceived stress, were negatively correlated with child vocalizations and conversational turns when infants were 6 and 12 months of age. Greater numbers of vocalizations and conversational turns were also associated with lower relative theta power and higher relative gamma power in 6- and 12-month baseline EEG - a pattern that might support subsequent language development.

ADHD Symptomatology, Executive Function and Cognitive Performance Differences between Family Foster Care and Control Group in ADHD-Diagnosed Children

Children in foster care have a high prevalence of attention deficit and hyperactivity disorder (ADHD) diagnosis, together with other difficulties in inattentive/hyperactive behaviors, executive and cognitive processes. Early exposure to adversity is a risk factor for developing ADHD via neurodevelopmental pathways. The goal of this research is (a) to study the cognitive and executive performance and inattentive/hyperactive behavior of ADHD-diagnosed children living in foster families in Spain, and (b) to analyze the role of placement variables in their performance. The sample was composed of 102 ADHD-diagnosed children aged 6- to 12-years-old, divided into two groups: 59 children living with non-relative foster families and 43 children not involved with protection services. Children’s executive function–inhibition, working memory, flexibility, attention, intellectual capacity, verbal comprehension, perceptive reasoning, working memory and processing speed were assessed using objective testing measures. At the same time, parents and teachers reported on children’s inattentive, hyperactive and impulsive behaviors. Children in foster care obtained lower scores in the general ability index than the control group after controlling the age at assessment. However, no differences were found in executive processes. Regarding placement factors, children with shorter exposure to adversities in their birth families and more time in foster care showed better executive performance. Professionals should consider the placement history of children in foster care and its influence on their symptomatology and cognitive capacities.

Temperament moderates the effects of early deprivation on infant attention

Institutional care has been shown to increase the risk of attention problems in children, but some children are more sensitive to their environment, both for better and for worse. With this in mind, the current study examined the moderating role of temperament (falling reactivity) between early adversity and attention skills. Six- to 15-month-old infants residing in institutions (n = 63) and infants reared by their biological families from low socioeconomic environments (n = 59) were recruited. The infants' attention skills were measured by calculating the length of time they spent looking at toys. The infants' temperaments were measured by a subscale of the Infant Behavior Questionnaire (falling reactivity/rate of recovery from distress). The findings were in line with the differential susceptibility theory. Compared to infants with high levels of falling reactivity, infants with lower levels of falling reactivity had better attention skills if they were in a family group, but they had lower attention skills if they were residing in institutions. The attention skills of the infants who had higher scores for falling reactivity did not appear to be affected by the adverse environment.

Defining the role of exposure to ACEs in ADHD: Examination in a national sample of US children

BACKGROUND

Clinical presentations of ADHD vary according to biological and environmental developmental influences. An emerging field of research has demonstrated relationships between exposure to adverse childhood experiences (ACEs) and ADHD prevalence, particularly in high-risk samples. However, research examining the combined role of traditional risk factors of ADHD and ACEs is limited, and reliance on high-risk samples introduces sampling bias.

OBJECTIVE

To examine the influence of ACEs on ADHD diagnosis using a large, nationally representative sample of US children.

PARTICIPANTS AND SETTING

Nationally representative samples (2017 and 2018) of 40,075 parents from the National Survey of Children's Health (NSCH).

METHODS

We conducted logistic regression models to examine the association of ACEs and ADHD diagnosis, controlling for child and parent demographic variables and other risk factors.

RESULTS

Exposure to ACEs was significantly associated with parent-reported ADHD diagnosis, controlling for known parental and child-risk factors of ADHD. The association followed a gradient pattern of increased ADHD prevalence with additional exposures. Compared to children with no ACEs, the odds of an ADHD diagnosis were 1.39, 1.92, and 2.72 times higher among children with one, two and three or more ACEs. The ACE most strongly associated with the odds of ADHD was having lived with someone with mental illness closely followed by parent/guardian incarceration.

CONCLUSIONS

Results further strengthen the evidence that ACEs exposure is associated with increased ADHD prevalence. Clinicians should assess ACEs in the diagnosis of ADHD. Furthermore, results of the study lend support to the efforts of agencies (both institutional and state-level) promoting routine screening of ACEs in children.

Psychiatric outcomes following severe deprivation in early childhood: Follow-up of a randomized controlled trial at age 16

OBJECTIVE

Early psychosocial deprivation is associated with increased risk for psychopathology, yet few studies have examined outcomes in adolescents.

METHOD

At baseline (M age 22 months), 136 children from Bucharest, Romania, living in large institutions, were randomized into foster care (FCG) or to care as usual (CAUG). Caregivers completed psychiatric interviews regarding their children (52 FCG; 51 CAUG) at age 16 years (M = 16.67 years; SD = 0.78) to assess past year diagnoses and symptom counts. In addition, never-institutionalized community comparison children (n = 47) were included.

RESULTS

Ever-institutionalized children had higher rates of meeting criteria for any psychiatric disorder and higher symptom counts of internalizing, externalizing, attention-deficit/hyperactivity, and substance use disorders compared to never-institutionalized children (ps < .05). Using intent-to-treat analyses, we found that children in the CAUG had more than twice the rate of psychiatric disorders than children in the FCG (OR = 2.48, 95% CI [1.12, 5.48]). Furthermore, children in foster care who remained in their original placement did not significantly differ in their rates of psychiatric disorders compared to never-institutionalized children.

CONCLUSIONS

There are many ways children can be separated from parents, including placement into institutional care. The current findings indicate that such placements are associated with significant risks for psychopathology. Moreover, we provide causal evidence for the long-lasting positive effect of foster care in reducing the risk of psychopathology in adolescence, especially among those in stable placements. These results provide strong evidence that early and stable placements into quality foster care may mitigate risk for psychopathology following severe early psychosocial deprivation. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Prefrontal Cortex Development in Health and Disease: Lessons from Rodents and Humans

The role of the prefrontal cortex (PFC) takes center stage among unanswered questions in modern neuroscience. The PFC has a Janus-faced nature: it enables sophisticated cognitive and social abilities that reach their maximum expression in humans, yet it underlies some of the devastating symptoms of psychiatric disorders. Accordingly, appropriate prefrontal development is crucial for many high-order cognitive abilities and dysregulation of this process has been linked to various neuropsychiatric diseases. Reviewing recent advances in the field, with a primary focus on rodents and humans, we highlight why, despite differences across species, a cross-species approach is a fruitful strategy for understanding prefrontal development. We briefly review the developmental contribution of molecules and extensively discuss how electrical activity controls the early maturation and wiring of prefrontal areas, as well as the emergence and refinement of input-output circuitry involved in cognitive processing. Finally, we highlight the mechanisms of developmental dysfunction and their relevance for psychiatric disorders.

Adolescent cognitive control and mediofrontal theta oscillations are disrupted by neglect: Associations with transdiagnostic risk for psychopathology in a randomized controlled trial

Children that have experienced psychosocial neglect display impairments in self-monitoring and controlling their behavior (cognitive control) and are at broad, transdiagnostic risk for psychopathology. However, the neural underpinnings of such effects remain unclear. Event-related mediofrontal theta oscillations reflect a neural process supporting cognitive control that may relate to transdiagnostic psychopathology risk. Recent work demonstrates reduced mediofrontal theta in rodent models of neglect; however, similar findings have not been reported in humans. Here, 136 children reared in Romanian institutions were randomly assigned to either a high-quality foster care intervention and placed with families or remained in institutions; 72 never-institutionalized children served as a comparison group. The intervention ended at 54 months; event-related mediofrontal theta and psychopathology were assessed at 12- and 16-year follow-up assessments. Institutional rearing (neglect) predicted reduced mediofrontal theta by age 16, which was linked to heightened transdiagnostic risk for psychopathology (P factor); no specific associations with internalizing/externalizing factors were present once transdiagnostic risk was accounted for. Earlier placement into foster care yielded greater mediofrontal activity by age 16. Moreover, foster care placement was associated with the developmental trajectory of mediofrontal theta across the adolescent period (ages 12–16), which was, in turn, associated with greater reductions in transdiagnostic risk across this same period. These data reflect the first experimental evidence that the development of mediofrontal theta is impacted by removal from situations of neglect in humans, and further characterizes the importance of studying developmental change in mediofrontal theta during the adolescent period.

Time-Dependent Effects of Exposure to Physical and Sexual Violence on Psychopathology Symptoms in Late Childhood: In Search of Sensitive Periods in Development

OBJECTIVE

Exposure to interpersonal violence is a known risk factor for psychopathology. However, it is unclear whether there are sensitive periods when exposure is most deleterious. We aimed to determine whether there were time periods when physical or sexual violence exposure was associated with greater child psychopathology.

METHOD

This study (N = 4,580) was embedded in Generation R, a population-based prospective birth cohort. Timing of violence exposure, reported through maternal reports (child age, 10 years) was categorized by age at first exposure, defined as: very early (0-3 years), early (4-5 years), middle (6-7 years), and late (8+ years) childhood. Using Poisson regression, we assessed the association between timing of first exposure and levels of internalizing and externalizing symptoms, using the Child Behavior Checklist at age 10 years.

RESULTS

Violence exposure at any age was associated with higher internalizing (physical violence: risk ratio [RR] = 1.46, p < 0.0001; sexual violence: RR = 1.30, p < .0001) and externalizing symptoms (physical violence: RR = 1.52, p < 0.0001; sexual violence: RR = 1.31, p = 0.0005). However, the effects of violence were time dependent: compared to children exposed at older ages, children first exposed during very early childhood had greater externalizing symptoms. Sensitivity analyses suggested that these time-based differences emerged slowly across ages 1.5, 3, 6, and 10 years, showing a latency between onset of violence exposure and emergence of symptoms, and were unlikely to be explained by co-occurring adversities.

CONCLUSION

Interpersonal violence is harmful to childhood mental health regardless of when it occurs. However, very early childhood may be a particularly sensitive period when exposure results in worse psychopathology outcomes. Results should be replicated in fully prospective designs.

Early Deprivation Revisited: Contemporary Studies of the Impact on Young Children of Institutional Care

There is clear evidence that early deprivation in the form of early institutional care affects children both immediately and long after they are removed from the institution. This article reviews the modern literature on the impact of institutional care from animal models to longitudinal studies in humans. Importantly, we examine the current understanding of neuroendocrine regulation in the context of early deprivation. We discuss the opportunities and limitations of studying the effects of deprivation in previously institutionalized children, review behavioral findings and related neurobiological studies, and address the physical health ramifications of institutional care. Finally, we touch on future directions for both science and intervention.

Socioeconomic and experiential influences on the neurobiology of language development

PURPOSE

The process by which young children acquire language is an incredible feat subserved by neurobiological language circuitry. While the foundations of brain structure and function are genetically determined, children's experiences during sensitive periods in early life have a significant influence on the development of language systems. The purpose of this review is to provide practitioners with a comprehensive summary of foundational and recent research on the ways that children's early experiences-both favorable and adverse-may influence the neuroanatomy and neurophysiology underlying language development. A specific focus is given to the burgeoning neuroimaging evidence of relationships between socioeconomic status (SES) and brain development, as well as to emerging research on proximal experiences that may serve as the direct mechanisms by which SES influences language development.

CONCLUSION

Findings from the neuroscience field have direct implications for practice in speech language pathology. Specifically, clinicians can have immense influence on crafting supportive language environments during windows of maximal neural influence, both via direct intervention and parent coaching. Practical suggestions are provided for translating research findings to practice.

Frontal brain maturation and the stability of children's shyness

Recent evidence suggests that relative to nonshy children, shy children exhibit a lower overall frontal EEG alpha/delta ratio (ADR) during middle childhood, possibly reflecting relatively less frontal brain maturation at this age. We examined this same ADR measure in relation to the stability of observed shyness and parent-reported child social anxiety measured across two laboratory visits separated by approximately 1 year during late childhood in 51 children (33% female, age range 10-16 years). We found that the overall frontal ADR score was significantly lower among children with high, stable observed shyness and parent-reported child social anxiety compared to children in the low, stable class. Findings provide convergent evidence suggesting that the stability of shyness in late childhood may be linked to relatively less overall frontal brain maturation at this age. We speculate on the adaptive function of delaying frontal brain maturation in the origins and maintenance of children's shyness.

The long-term effects of institutional rearing, foster care intervention and disruptions in care on brain electrical activity in adolescence

Exposure to early psychosocial deprivation as a result of institutional care disrupts typical brain development. The Bucharest Early Intervention Project (BEIP) is the first longitudinal study to investigate the neurodevelopment of institutionalized infants randomized to a foster care (FCG) intervention versus care as usual (CAUG). Here, we present findings from a follow-up assessment of brain electrical activity as indexed by resting EEG at age 16 years. In addition, we examined the effects of disruption of foster care placement (e.g. the number of moves among foster care placements) on brain electrical activity. Resting-state EEG was collected from 48 CAUG, 46 FCG and 48 never institutionalized (NIG) control participants. Absolute (µV² ) and relative (proportion) power were computed from eyes closed, resting EEG data for theta, alpha and beta frequency bands. The CAUG displayed higher relative theta and lower relative alpha power compared to the FCG at 16 years of age. The FCG showed brain activity comparable to the NIG. The results further showed that disruptions following the original foster care placement had an adverse effect on brain electrical activity. Within the foster care group, there were no effects of age of placement on EEG power. Placement of children who have experienced early institutional rearing into stable foster care settings ensure long-term improvement in brain functioning.

The Consequences of Foster Care Versus Institutional Care in Early Childhood on Adolescent Cardiometabolic and Immune Markers: Results From a Randomized Controlled Trial

OBJECTIVE

Children exposed to institutional rearing often exhibit problems across a broad array of developmental domains. We compared the consequences of long-term, high-quality foster care versus standard institution-based care, which began in early childhood on cardiometabolic and immune markers assessed at the time of adolescence.

METHODS

The Bucharest Early Intervention Project is a longitudinal investigation of children institutionalized during early childhood (ages 6 to 30 months at baseline) who were subsequently randomized to either high-quality foster care or continued institutional care. At the age of 16 years, 127 respondents participated in a biomarker collection protocol, including 44 institutionalized children randomly assigned to receive care as usual, 41 institutionalized children randomized to be removed from institutional care and placed in high-quality foster care in infancy, and a control group of 42 demographically matched children raised in biological families. Outcomes included body mass index (BMI), systolic and diastolic blood pressure, C-reactive protein, interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor α, glycosylated hemoglobin A1c, and Epstein-Barr virus antibody titers.

RESULTS

Early institutional rearing was not associated with differences in cardiometabolic or immune markers. Randomization to foster care and age of placement into foster care were also unrelated to these markers, with the exception of BMI z-score, where children assigned to care as usual had lower BMI z-scores relative to children assigned to foster care (-0.23 versus 0.08, p = .06), and older age at placement was associated with lower BMI (β = -0.07, p = .03).

CONCLUSIONS

The impact of institutional rearing on measures of cardiometabolic health and immune system functioning is either absent or not evident until later in development. These findings provide new insights into the biological embedding of adversity and how it varies developmentally and across regulatory systems and adversity type.

CLINICAL TRIAL REGISTRATION

NCT00747396.

Effects of Maternal Psychopathology and Education Level on Neurocognitive Development in Infants of Adolescent Mothers Living in Poverty in Brazil

BACKGROUND

Adolescent motherhood remains common in developing countries and is associated with risk factors that adversely impact infant neurodevelopment, including poverty, low maternal education, and increased maternal psychopathology. Yet, no published work has assessed how these factors affect early brain development in developing countries.

METHODS

This pilot study examined effects of maternal psychopathology and education on early neurocognitive development in a sample of adolescent mothers (N = 50, final n = 31) and their infants living in poverty in São Paulo, Brazil. Maternal symptoms of anxiety, depression, and attention-deficit/hyperactivity disorder and education level were assessed during pregnancy. Infant neurocognitive development was assessed at 6 months of age, with oscillatory power and functional connectivity in the theta (4-6 Hz), alpha (6-9 Hz), and gamma (30-50 Hz) frequencies derived from resting-state electroencephalography; temperament (negative affect, attention, and regulation); and cognitive, language, and motor skills. Cluster-based permutation testing and graph-theoretical methods were used to identify alterations in oscillatory power and connectivity that were associated with maternal psychopathology and education. Correlations between power and connectivity alterations were examined in relation to infants' overt cognitive behavioral abilities.

RESULTS

Increased maternal anxiety and lower maternal education were associated with weaker oscillatory connectivity in alpha-range networks. Infants with the weakest connectivity in the alpha network associated with maternal anxiety also showed the lowest cognitive ability. Greater maternal anxiety and attention-deficit/hyperactivity disorder were associated with increased absolute and relative theta power.

CONCLUSIONS

Our findings highlight the importance of addressing maternal psychopathology and improving education in poor adolescent mothers to prevent negative effects on infant neurodevelopment.

Language Outcomes in Adults with a History of Institutionalization: Behavioral and Neurophysiological Characterization

Impoverished early care environments are associated with developmental deficits in children raised in institutional settings. Despite the accumulation of evidence regarding deficits in general cognitive functioning in this population, less is known about the impact of institutionalization on language development at the level of brain and behavior. We examined language outcomes in young adults and adolescents raised in institutions (n = 23) as compared to their socioeconomic status and age peers raised in biological families (n = 24) using a behavioral language assessment and linguistic event-related potentials (ERPs). Controlling for intelligence, adults with a history of institutionalization demonstrated deficits in lexical and grammatical development and spelling. Analyses of ERP data revealed significant group differences in the dynamic processing of linguistic stimuli. Adults with a history of institutionalization displayed reduced neural sensitivity to violations of word expectancy, leading to reduced condition effects for temporo-spatial factors that tentatively corresponded to the N200, P300/N400, and phonological mismatch negativity. The results suggest that language is a vulnerable domain in adults with a history of institutionalization, the deficits in which are not explained by general developmental delays, and point to the pivotal role of early linguistic environment in the development of the neural networks involved in language processing.

Early Parenting Intervention and Adverse Family Environments Affect Neural Function in Middle Childhood

BACKGROUND

Growing work points to the negative impact of early adverse experiences on the developing brain. An outstanding question concerns the extent to which early intervention can normalize trajectories of brain development in at-risk children. We tested this within the context of a randomized clinical trial of an early parenting program, the Attachment and Biobehavioral Catch-up (ABC), delivered to parents and infants monitored for maltreatment by Child Protective Services.

METHODS

Families participated in the randomized clinical trial when children were 2.5 years of age or younger. Parenting and home adversity was measured at baseline. Children were followed longitudinally, and resting brain activity was measured electrophysiologically (n = 106) when children reached 8 years of age. Spectral power was quantified and compared across children assigned to the experimental intervention (ABC), a control intervention, and a low-risk comparison group (n = 76) recruited at the follow-up assessment.

RESULTS

Higher early home adversity was associated with electrophysiological profiles indicative of cortical delays/immaturity in middle childhood, based on relatively greater power in lower frequency bands (theta, 4-6 Hz, and low alpha, 6-9 Hz) and lower power in a higher frequency band (high alpha, 9-12 Hz). Children assigned to ABC showed relatively greater high-frequency power (beta, 12-20 Hz) than children assigned to the control intervention. Beta power in the ABC did not differ from that of the low-risk comparison group.

CONCLUSIONS

Maltreatment risk and home adversity can affect indicators of middle childhood brain maturation. Early parenting programs can support more normative patterns of neural function during middle childhood.

Early Sexual Trauma Exposure and Neural Response Inhibition in Adolescence and Young Adults: Trajectories of Frontal Theta Oscillations During a Go/No-Go Task

OBJECTIVE

Trauma, particularly when experienced early in life, can alter neurophysiologic and behavioral development, thereby increasing risk for substance use disorders and related psychopathology. However, few studies have empirically examined trauma using well-characterized developmental samples that are followed longitudinally.

METHOD

The association of assaultive, non-assaultive, and sexual assaultive experiences before 10 years of age with developmental trajectories of brain function during response inhibition was examined by measuring electrophysiologic theta and delta oscillations during no-go and go conditions in an equal probability go/no-go task. Data were drawn from the Collaborative Study of the Genetics of Alcoholism (COGA) prospective cohort, composed of offspring who were aged 12 through 22 years at enrollment from high-risk and comparison families, with follow-ups at 2-year intervals since 2004. In addition, other important predictors of neurophysiologic functioning (eg, substance use, impulsivity, and parental alcohol use disorders) were investigated. Moreover, associations of neurophysiologic functioning with alcohol and cannabis use disorder symptom counts and externalizing and internalizing psychopathology were examined.

RESULTS

Individuals exposed to sexual assaultive trauma before 10 years of age had slower rates of change in developmental trajectories of no-go frontal theta during response inhibition. Importantly, effects remained significant after accounting for exposure to other traumatic exposures, such as parental history of alcohol use disorder and participants' substance use, but not measures of impulsivity. Further, slower rates of change in no-go frontal theta adolescent and young adult development were associated with increased risk for alcohol use disorder symptoms and internalizing psychopathology, but not for cannabis use disorder symptoms or externalizing psychopathology.

CONCLUSION

Childhood sexual assault is associated with atypical frontal neurophysiologic development during response inhibition. This could reflect alterations in frontal lobe development, synaptic pruning, and/or cortical maturation involving neural circuits for inhibitory control. These same areas could be associated with increased risk for young adult alcohol use disorder symptoms and internalizing psychopathology. These findings support the hypothesis that changes in neurocognitive development related to early sexual trauma exposure could increase the risk for mental health and substance use problems in young adulthood.

Long-term effects of institutional rearing, foster care, and brain activity on memory and executive functioning

Children experiencing psychosocial deprivation as a result of early institutional rearing demonstrate many difficulties with memory and executive functioning (EF). To date, there is scant evidence that foster care placement remediates these difficulties during childhood. The current study examined longitudinal trajectories of memory and EF from childhood to adolescence in the Bucharest Early Intervention Project, a randomized controlled trial of foster care for institutionally reared children. We demonstrate that both ever- and never-institutionalized children show age-related improvements on several measures of memory and EF from age 8 to 16. Distinct patterns were observed for different domains of functioning: (i) Early-emerging disparities in attention and short-term visual memory, as well as spatial planning and problem solving, between ever- and never-institutionalized children persisted through adolescence; (ii) the gap in spatial working memory between ever- and never-institutionalized children widened by adolescence; and (iii) early difficulties in visual-spatial memory and new learning among children in foster care were mitigated by adolescence. Secondary analyses showed that higher resting EEG alpha power at age 8 predicted better EF outcomes in several domains at age 8, 12, and 16. These results suggest that early institutional rearing has enduring consequences for the development of memory and EF, with the possibility of catch-up among previously institutionalized children who start out with higher levels of problems. Finally, interindividual differences in brain activity relate to memory and EF across ages, thus highlighting one potential biological pathway through which early neglect impacts long-term cognitive functioning.

Rapid Infant Prefrontal Cortex Development and Sensitivity to Early Environmental Experience

Over the last fifteen years, the emerging field of developmental cognitive neuroscience has described the relatively late development of prefrontal cortex in children and the relation between gradual structural changes and children's protracted development of prefrontal-dependent skills. Widespread recognition by the broader scientific community of the extended development of prefrontal cortex has led to the overwhelming perception of prefrontal cortex as a "late developing" region of the brain. However, despite its supposedly protracted development, multiple lines of research have converged to suggest that prefrontal cortex development may be particularly susceptible to individual differences in children's early environments. Recent studies demonstrate that the impacts of early adverse environments on prefrontal cortex are present very early in development: within the first year of life. This review provides a comprehensive overview of new neuroimaging evidence demonstrating that prefrontal cortex should be characterized as a "rapidly developing" region of the brain, discusses the converging impacts of early adversity on prefrontal circuits, and presents potential mechanisms via which adverse environments shape both concurrent and long-term measures of prefrontal cortex development. Given that environmentally-induced disparities are present in prefrontal cortex development within the first year of life, translational work in intervention and/or prevention science should focus on intervening early in development to take advantages of this early period of rapid prefrontal development and heightened plasticity.

Early Childhood Adverse Experiences, Inferior Frontal Gyrus Connectivity, and the Trajectory of Externalizing Psychopathology

OBJECTIVE

Early adverse childhood experiences (ACEs) have been linked to the development of both internalizing and externalizing psychopathology. In our prior work, we found that ACEs predicted reductions in the volume of the inferior frontal gyrus (IFG), a brain region important for impulse control and emotion regulation. Here we tested the hypothesis that ACEs might influence child behavioral outcomes through an impact on IFG functional connectivity, which may influence impulsive or risk-taking behavior.

METHOD

We examined the effects of prospectively assessed ACEs on IFG connectivity in childhood, and their relationship to the trajectory of subsequent psychopathology from late school age and early adolescence, using data from an 11-year longitudinal study of children starting in preschool that included 3 waves of resting state functional connectivity across childhood and early adolescence.

RESULTS

ACEs predicted functional connectivity of both left and right IFG. Multi-level modeling of symptoms across 3 waves of assessments indicated that more ACEs predicted both internalizing and externalizing symptoms. However, altered IFG connectivity specifically predicted greater externalizing symptoms over time in middle childhood and early adolescence, as compared to internalizing symptoms. Longitudinal modeling indicating that the relationships between externalizing and functional connectivity were maintained across 3 waves of functional connectivity assessment.

CONCLUSION

These findings underscore the relationship of ACEs to later psychopathology, and suggest that connectivity of the IFG, a region known to play an important role in impulse control and emotion regulation, may play a key role in the risk trajectory of ACEs to externalizing problems. However, further work is needed to understand whether these relationships reflect a direct effect of ACEs or whether ACEs are a marker for other environmental or genetic factors that may also influence brain development and behavior.

Age-related changes in baroreflex sensitivity and cardiac autonomic tone in children mirrored by regional brain gray matter volume trajectories

BackgroundThe baroreflex and central autonomic brain regions together control the cardiovascular system. Baroreflex sensitivity (BRS) decreases with age in adults. Age-related changes in brain regions for cardiovascular control in children are unknown. We studied age-related changes in BRS, cardiac autonomic tone, and gray matter volume (GMV) of brain regions associated with cardiovascular control.MethodsBeat-to-beat blood pressure and heart rate (HR) were recorded in 49 children (6-14 years old). Spontaneous BRS was calculated by the sequence method. Cardiac autonomic tone was measured by spectral analysis of HR variability. GMV was measured using voxel-based morphometryin 112 healthy children (5-18 years old).ResultsAge-related changes in BRS were significantly different in children <10 years and ≥10 years. Age-related changes in GMV in regions of interest (ROI) were also significantly different between children <10 and ≥10 years and between children <11 and ≥11 years. However, age-related changes in cardiac autonomic tone were progressive.ConclusionsSignificant changes in BRS trajectories between <10 and ≥10 years may be associated with similar age-related changes of GMV in brain ROI. This new knowledge will guide future studies examining whether childhood cardiovascular disruption manifests as deviated maturation trajectories of specific brain regions.