Childhood socioeconomic status and the pace of structural neurodevelopment: accelerated, delayed, or simply different?

Depression, brain structure and socioeconomic status: A UK Biobank study

BACKGROUND

Depression results from interactions between biological, social, and psychological factors. Literature shows that depression is associated with abnormal brain structure, and that socioeconomic status (SES) is associated with depression and brain structure. However, limited research considers the interaction between each of these factors.

METHODS

Multivariate regression analysis was conducted using UK Biobank data on 39,995 participants to examine the relationship between depression and brain volume in 23 cortical regions for the whole sample and then separated by sex. It then examined whether SES affected this relationship.

RESULTS

Eight out of 23 brain areas had significant negative associations with depression in the whole population. However, these relationships were abolished in seven areas when SES was included in the analysis. For females, three regions had significant negative associations with depression when SES was not included, but only one when it was. For males, lower volume in six regions was significantly associated with higher depression without SES, but this relationship was abolished in four regions when SES was included. The precentral gyrus was robustly associated with depression across all analyses.

LIMITATIONS

Participants with conditions that could affect the brain were not excluded. UK Biobank is not representative of the general population which may limit generalisability. SES was made up of education and income which were not considered separately.

CONCLUSIONS

SES affects the relationship between depression and cortical brain volume. Health practitioners and researchers should consider this when working with imaging data in these populations.

Hierarchical individual variation and socioeconomic impact on personalized functional network topography in children

BACKGROUND

The spatial layout of large-scale functional brain networks exhibits considerable inter-individual variability, especially in the association cortex. Research has demonstrated a link between early socioeconomic status (SES) and variations in both brain structure and function, which are further associated with cognitive and mental health outcomes. However, the extent to which SES is associated with individual differences in personalized functional network topography during childhood remains largely unexplored.

METHODS

We used a machine learning approach-spatially regularized non-negative matrix factorization (NMF)-to delineate 17 personalized functional networks in children aged 9-10 years, utilizing high-quality functional MRI data from 6001 participants in the Adolescent Brain Cognitive Development study. Partial least square regression approach with repeated random twofold cross-validation was used to evaluate the association between the multivariate pattern of functional network topography and three SES factors, including family income-to-needs ratio, parental education, and neighborhood disadvantage.

RESULTS

We found that individual variations in personalized functional network topography aligned with the hierarchical sensorimotor-association axis across the cortex. Furthermore, we observed that functional network topography significantly predicted the three SES factors from unseen individuals. The associations between functional topography and SES factors were also hierarchically organized along the sensorimotor-association cortical axis, exhibiting stronger positive associations in the higher-order association cortex. Additionally, we have made the personalized functional networks publicly accessible.

CONCLUSIONS

These results offer insights into how SES influences neurodevelopment through personalized functional neuroanatomy in childhood, highlighting the cortex-wide, hierarchically organized plasticity of the functional networks in response to diverse SES backgrounds.

Associations between prenatal exposure to environmental phenols and child neurodevelopment at two years of age in a South African birth cohort

OBJECTIVE

Evidence suggests that prenatal environmental phenol exposures negatively impact child neurodevelopment, however there is little research on the effects of mixtures of multiple phenol exposures. We analyzed associations between prenatal exposure to phenol mixtures and cognitive neurodevelopment at two years of age among 545 mother-child pairs from the South African Drakenstein Child Health Study.

MATERIAL AND METHODS

We measured maternal urine environmental phenol concentrations once during the second trimester of pregnancy. We used the Bayley Scales of Infant and Toddler Development III to assess cognitive development at two years of age. We used linear regression models adjusted for maternal HIV status, maternal age, ethnicity, prenatal tobacco exposure, child sex, and socioeconomic status (SES) to examine individual associations. We compared four mixture methods: self-organizing maps (SOM), Bayesian kernel machine regression (BKMR), quantile-based G-computation (qgcomp) and weighted quantile sum (WQS) regression to explore joint effects of the exposure mixture. We assessed effect modification by SES, sex, prenatal tobacco exposure, and ethnicity.

RESULTS

Across all methods, we found no association between individual phenol exposures or the joint exposure mixture with the cognitive score. Prenatal tobacco exposure modified the association between pentachlorophenol (PCP) and cognitive neurodevelopment (interaction p-value = 0.012), with higher PCP concentrations associated with lower cognitive scores among non-smokers (beta = - 2.17; 95% CI: -3.83, -0.51). Sex modified the association between bisphenol A (BPA) and cognitive neurodevelopment (interaction p-value = 0.021), with males having a significant adverse association (beta = -1.39; 95% CI: -2.54, -0.23). SES modified the association between bisphenol S (BPS) and cognitive neurodevelopment (interaction p-value = 0.003), with individuals of moderate-high SES having a significant adverse association (beta = -1.84; 95% CI: -3.26, 0.06) CONCLUSION: While we found no main effects of prenatal phenol exposure on cognitive neurodevelopment, the associations with PCP, BPA, and BPS were more pronounced among certain subgroups.

Early onset and increasing disparities in neurodevelopmental delays from birth to age 6 in children from low socioeconomic backgrounds

OBJECTIVE

To analyze the complex relationship between socioeconomic status (SES) and neurodevelopmental achievements by investigating the temporal dynamics of these associations from birth to age 6.

METHODS

This retrospective cohort study was conducted over 6 years using population-based data from the National Health Insurance Service and integrated data from the National Health Screening Program for Infants and Children. Participants were children born between 2009 and 2011 in Korea without neurodevelopmental delays with potential developmental implications. We analyzed results from the Korean Developmental Screening Test, administered at age 6, which covered overall assessment and six domains of gross and fine motor function, cognition, language, sociality, and self-care. The secondary outcome was to determine when neurodevelopmental outcomes began after birth and how these differences changed over time.

RESULTS

Of 276,167 individuals (49.2% males), 66,325, 138,980, and 60,862 had low, intermediate, and high SES, respectively. Neurodevelopmental delays observed across all developmental domains were more prevalent in the low-SES group than in the high-SES group. Disparities in neurodevelopment according to these statuses were apparent as early as age 2 and tended to increase over time (interaction, P < 0.001). The cognition and language domains exhibited the most substantial disparities between SES levels. These disparities persisted in subgroup analyses of sex, birthweight, head circumference, birth data, and breastfeeding variables.

CONCLUSIONS

Low SES was significantly associated with an increased risk of adverse neurodevelopmental outcomes in preschool children, particularly those affecting cognitive and language domains. These differences manifested in early childhood and widened over time.

Environmental and neurodevelopmental contributors to youth mental illness

While a myriad of factors likely contribute to the development of mental illness in young people, the social environment (including early adverse experiences) in concert with neurodevelopmental alterations is undeniably important. A number of influential theories make predictions about how and why neurodevelopmental alterations may mediate or moderate the effects of the social environment on the emergence of mental illness. Here, we discuss current evidence supporting each of these theories. Although this area of research is rapidly growing, the body of evidence is still relatively limited. However, there exist some consistent findings, including increased striatal reactivity during positive affective processing and larger hippocampal volumes being associated with increased vulnerability or susceptibility to the effects of social environments on internalizing symptoms. Limited longitudinal work has investigated neurodevelopmental mechanisms linking the social environment with mental health. Drawing from human research and insights from animal studies, we propose an integrated mediation-moderation model and outline future research directions to advance the field.

Functional brain connectivity predictors of prospective substance use initiation and their environmental correlates

BACKGROUND

Early substance use initiation (SUI) places youth at substantially higher risk for later substance use disorders. Furthermore, adolescence is a critical period for the maturation of brain networks, the pace and magnitude of which are susceptible to environmental influences and may shape risk for SUI.

METHODS

We examined whether patterns of functional brain connectivity during rest (rsFC), measured longitudinally in pre-and-early adolescence, can predict future SUI. Next, in an independent sub-sample, we tested whether these patterns are associated with earlier environmental exposures, specifically neighborhood pollution and socioeconomic dimensions. We utilized data from the Adolescent Brain Cognitive Development (ABCD) Study®. SUI was defined as first-time use of at least one full dose of alcohol, nicotine, cannabis, or other drugs. We created a control group (N = 228) of participants without SUI who were matched with the SUI group (N = 233) on age, sex, race/ethnicity, and parental income and education.

RESULTS

Multivariate analysis showed that whole-brain rsFC from 9-10 to 11-12 years of age (prior to SUI) prospectively differentiated the SUI and control groups. The SUI-related rsFC pattern was also related to aging in both groups, suggesting a pattern of accelerated maturation in the years prior to SUI. This same pattern of rsFC was predicted by higher pollution, but not neighborhood disadvantage (adjusted for family socioeconomic factors) in an independent sub-sample (N = 2,854).

CONCLUSION

Brain functional connectivity patterns in early adolescence that are linked to accelerated maturation can predict SUI in youth and are associated with exposure to pollution.

Parental emotional support, self-efficacy, and mental health problems among adolescents in Hong Kong: a moderated mediation approach

Introduction

Early signs of mental health issues may develop into severe mental illnesses over time. The influence of parental emotional support on adolescent mental health problems is well acknowledged. However, prior research has predominantly focused on psychological symptoms, often neglecting the somatic symptoms associated with mental health. Additionally, there has been insufficient exploration of the mediating role of self-efficacy and the relationship between socioeconomic status (SES) and adolescent mental health, particularly within the context of Hong Kong.

Methods

Using data from 3,613 adolescents aged 15 years from 109 schools in Hong Kong who participated in the Programme for International Student Assessment 2018, this study explored the relationship between parental emotional support and two dimensions of adolescent mental health symptoms (psychological and somatic symptoms), and the mediating effect of self-efficacy and the moderating role of SES.

Results

We found that parental emotional support significantly reduced psychological and somatic symptoms, primarily by enhancing self-efficacy. MoreovSES moderated these relationships, with the impact of parental emotional support on psychological symptoms being more pronounced among adolescents from lower SES backgrounds.

Discussion

This study deepens the understanding of the mechanisms underlying adolescent mental health in Hong Kong. By highlighting the importance of parental emotional support and self-efficacy, as well as the moderating effect of SES, the findings offer valuable insights for effective interventions aimed at improving adolescent mental health.

Associations of inflammation related prenatal adversities with neurodevelopment of offspring in one year: a longitudinal prospective birth cohort study

BACKGROUND

The recent Maternal Immune Activation (MIA) theory suggests maternal systemic inflammation may serve as a mediator in associations between prenatal maternal adversities and neurodevelopmental diseases in offspring. Given the co-exposure to multiple adversities may be experienced by pregnant person, it is unclear whether a quantitative index can be developed to characterize the inflammation related exposure level, and whether this index is associated with neurodevelopmental delays in offspring.

METHODS

Based on Jiangsu Birth Cohort (JBC), a total of 3051 infants were included in the analysis. Inflammation related Prenatal Adversity Index (IPAI) was constructed using maternal data. Neurodevelopmental outcomes were assessed using the Bayley Scales of Infant and Toddler Development, third edition, screening test in one year. Multivariate linear regression and Poisson regression model were performed to analyze the associations between IPAI and neurodevelopment in offspring.

RESULTS

Compared with "low IPAI" group, offspring with "high IPAI" have lower scores of cognition, receptive communication, expressive communication, and fine motor. The adjusted β were - 0.23 (95%CI: -0.42, -0.04), -0.47 (95%CI: -0.66, -0.28), -0.30 (95%CI: -0.49, -0.11), and - 0.20 (95%CI: -0.33, -0.06). Additionally, the elevated risk for noncompetent development of cognition and receptive communication among "high IPAI" group was observed. The relative risk [RR] and 95% confidence interval [CI] were 1.35 (1.01, 1.69) and 1.37 (1.09, 1.72).

CONCLUSIONS

Our results revealed a significant association between higher IPAI and lower scores across cognition, receptive communication, expressive communication, and fine motor domains, and an increased risk of noncompetent development in the cognition and receptive communication domains.

Prenatal environment is associated with the pace of cortical network development over the first three years of life

Environmental influences on brain structure and function during early development have been well-characterized, but whether early environments are associated with the pace of brain development is not clear. In pre-registered analyses, we use flexible non-linear models to test the theory that prenatal disadvantage is associated with differences in trajectories of intrinsic brain network development from birth to three years (n = 261). Prenatal disadvantage was assessed using a latent factor of socioeconomic disadvantage that included measures of mother's income-to-needs ratio, educational attainment, area deprivation index, insurance status, and nutrition. We find that prenatal disadvantage is associated with developmental increases in cortical network segregation, with neonates and toddlers with greater exposure to prenatal disadvantage showing a steeper increase in cortical network segregation with age, consistent with accelerated network development. Associations between prenatal disadvantage and cortical network segregation occur at the local scale and conform to a sensorimotor-association hierarchy of cortical organization. Disadvantage-associated differences in cortical network segregation are associated with language abilities at two years, such that lower segregation is associated with improved language abilities. These results shed light on associations between the early environment and trajectories of cortical development.

Depressive symptoms during the transition to adolescence: Left hippocampal volume as a marker of social context sensitivity

The transition to adolescence is a critical period for mental health development. Socio-experiential environments play an important role in the emergence of depressive symptoms with some adolescents showing more sensitivity to social contexts than others. Drawing on recent developmental neuroscience advances, we examined whether hippocampal volume amplifies social context effects in the transition to adolescence. We analyzed 2-y longitudinal data from the Adolescent Brain Cognitive Development (ABCD®) study in a diverse sample of 11,832 youth (mean age: 9.914 y; range: 8.917 to 11.083 y; 47.8% girls) from 21 sites across the United States. Socio-experiential environments (i.e., family conflict, primary caregiver's depressive symptoms, parental warmth, peer victimization, and prosocial school environment), hippocampal volume, and a wide range of demographic characteristics were measured at baseline. Youth's symptoms of major depressive disorder were assessed at both baseline and 2 y later. Multilevel mixed-effects linear regression analyses showed that negative social environments (i.e., family conflict, primary caregiver's depressive symptoms, and peer victimization) and the absence of positive social environments (i.e., parental warmth and prosocial school environment) predicted greater increases in youth's depressive symptoms over 2 y. Importantly, left hippocampal volume amplified social context effects such that youth with larger left hippocampal volume experienced greater increases in depressive symptoms in more negative and less positive social environments. Consistent with brain-environment interaction models of mental health, these findings underscore the importance of families, peers, and schools in the development of depression during the transition to adolescence and show how neural structure amplifies social context sensitivity.

Auditory Risk Factors at Birth and Language Development at 2 Years of Age: A Longitudinal Analysis

Aim. To analyze the relationship between auditory risk factors at birth and subsequent language development in toddlerhood. Methods. Participants are 136 children from a longitudinal birth cohort follow-up at age 2 years. They were divided into 2 groups: One comprising 105 children without hearing risk factors at birth and another comprising 31 children with auditory risk factors at birth but normal hearing. Results. In children with and without risk factors, the combination of socio-emotional, socio-economic, and auditory risk factors at birth significantly predicted language development at age 2 years. Family socio-economic status had a significant impact on overall child development, even after controlling for socio-emotional development and the presence of risk factors. Conclusions. The study was conducted in an upper-middle income country with a socialized health care system. It underscores the importance of a holistic approach to early childhood language development, taking into account biological, socioeconomic, and emotional factors.

Socioeconomic resources in youth are linked to divergent patterns of network integration/segregation across the brain's transmodal axis

Socioeconomic resources (SER) calibrate the developing brain to the current context, which can confer or attenuate risk for psychopathology across the lifespan. Recent multivariate work indicates that SER levels powerfully relate to intrinsic functional connectivity patterns across the entire brain. Nevertheless, the neuroscientific meaning of these widespread neural differences remains poorly understood, despite its translational promise for early risk identification, targeted intervention, and policy reform. In the present study, we leverage graph theory to precisely characterize multivariate and univariate associations between SER across household and neighborhood contexts and the intrinsic functional architecture of brain regions in 5,821 youth (9-10 years) from the Adolescent Brain Cognitive Development Study. First, we establish that decomposing the brain into profiles of integration and segregation captures more than half of the multivariate association between SER and functional connectivity with greater parsimony (100-fold reduction in number of features) and interpretability. Second, we show that the topological effects of SER are not uniform across the brain; rather, higher SER levels are associated with greater integration of somatomotor and subcortical systems, but greater segregation of default mode, orbitofrontal, and cerebellar systems. Finally, we demonstrate that topological associations with SER are spatially patterned along the unimodal-transmodal gradient of brain organization. These findings provide critical interpretive context for the established and widespread associations between SER and brain organization. This study highlights both higher-order and somatomotor networks that are differentially implicated in environmental stress, disadvantage, and opportunity in youth.

The central role of the individual in the history of brains

Every species' brain, body and behavior is shaped by the contingencies of their evolutionary history; these exert pressures that change their developmental trajectories. There is, however, another set of contingencies that shape us and other animals: those that occur during a lifetime. In this perspective piece, we show how these two histories are intertwined by focusing on the individual. We suggest that organisms--their brains and behaviors--are not solely the developmental products of genes and neural circuitry but individual centers of action unfolding in time. To unpack this idea, we first emphasize the importance of variation and the central role of the individual in biology. We then go over "errors in time" that we often make when comparing development across species. Next, we reveal how an individual's development is a process rather than a product by presenting a set of case studies. These show developmental trajectories as emerging in the contexts of the "the actual now" and "the presence of the past". Our consideration reveals that individuals are slippery-they are never static; they are a set of on-going, creative activities. In light of this, it seems that taking individual development seriously is essential if we aspire to make meaningful comparisons of neural circuits and behavior within and across species.

Outdoor air pollution and brain development in childhood and adolescence

Exposure to outdoor air pollution has been linked to adverse health effects, including potential widespread impacts on the CNS. Ongoing brain development may render children and adolescents especially vulnerable to neurotoxic effects of air pollution. While mechanisms remain unclear, promising advances in human neuroimaging can help elucidate both sensitive periods and neurobiological consequences of exposure to air pollution. Herein we review the potential influences of air pollution exposure on neurodevelopment, drawing from animal toxicology and human neuroimaging studies. Due to ongoing cellular and system-level changes during childhood and adolescence, the developing brain may be more sensitive to pollutants' neurotoxic effects, as a function of both timing and duration, with relevance to cognition and mental health. Building on these foundations, the emerging field of environmental neuroscience is poised to further decipher which air toxicants are most harmful and to whom.

Structural and functional brain correlates of socioeconomic status across the life span: A systematic review

It is well-established that higher socioeconomic status (SES) is associated with improved brain health. However, the effects of SES across different life stages on brain structure and function is still equivocal. In this systematic review, we aimed to synthesise findings from life course neuroimaging studies that investigated the structural and functional brain correlates of SES across the life span. The results indicated that higher SES across different life stages were independently and cumulatively related to neural outcomes typically reflective of greater brain health (e.g., increased cortical thickness, grey matter volume, fractional anisotropy, and network segregation) in adult individuals. The results also demonstrated that the corticolimbic system was most commonly impacted by socioeconomic disadvantages across the life span. This review highlights the importance of taking into account SES across the life span when studying its effects on brain health. It also provides directions for future research including the need for longitudinal and multimodal research that can inform effective policy interventions tailored to specific life stages.

Screen time, brain network development and socio-emotional competence in childhood: moderation of associations by parent-child reading

BACKGROUND

Screen time in infancy is linked to changes in social-emotional development but the pathway underlying this association remains unknown. We aim to provide mechanistic insights into this association using brain network topology and to examine the potential role of parent-child reading in mitigating the effects of screen time.

METHODS

We examined the association of screen time on brain network topology using linear regression analysis and tested if the network topology mediated the association between screen time and later socio-emotional competence. Lastly, we tested if parent-child reading time was a moderator of the link between screen time and brain network topology.

RESULTS

Infant screen time was significantly associated with the emotion processing-cognitive control network integration (p = 0.005). This network integration also significantly mediated the association between screen time and both measures of socio-emotional competence (BRIEF-2 Emotion Regulation Index, p = 0.04; SEARS total score, p = 0.04). Parent-child reading time significantly moderated the association between screen time and emotion processing-cognitive control network integration (β = -0.640, p = 0.005).

CONCLUSION

Our study identified emotion processing-cognitive control network integration as a plausible biological pathway linking screen time in infancy and later socio-emotional competence. We also provided novel evidence for the role of parent-child reading in moderating the association between screen time and topological brain restructuring in early childhood.

Aspects of Area Deprivation Index in Relation to Hippocampal Volume Among Children

Importance

Area deprivation index (ADI) has been shown to be associated with reduced hippocampal volume (HV) among youths. The social environment may interact with the association between ADI and HV.

Objective

To investigate which aspects of ADI are uniquely associated with bilateral HV and whether school and family environments have moderating interactions in associations between ADI and HV.

Design, Setting, and Participants

This cross-sectional study used data from the Adolescent Brain and Cognitive Development (ABCD) study. Participants aged 9 and 10 years were recruited from 21 sites in the US between September 2016 and August 2018. Data analysis was performed between March 2023 and April 2024.

Exposures

ADI aspects were derived from participant primary home addresses provided by parents or guardians.

Main Outcomes and Measures

HV was automatically segmented from structural brain images ascertained from magnetic resonance imaging. Multiple generalized linear mixed modeling tested associations between 9 indices of ADI and bilateral HV, with family groups and recruitment sites as random effects. After stepwise backward selection, models were adjusted for individual-level covariates, including age, sex, race and ethnicity, parental education, household income, and estimated intracranial volume.

Results

This study included 10 114 participants aged 9 and 10 years (median [IQR] age, 9.92 [9.33-10.48] years; 5294 male [52.3%]; 200 Asian [2.0%], 1411 Black [14.0%], and 6655 White [65.8%]; 1959 Hispanic [19.4%]). After stepwise backward selection and adjusting for covariates, only the percentage of neighborhood-level single-parent households was associated with right HV (adjusted β per 1-SD increase in single-parent households, -0.03; 95% CI, -0.06 to -0.01; P = .01). School environment interacted with neighborhood-level single-parent households in its association with right HV (adjusted β per 1-SD increase in score, 0.02; 95% CI, 0.01 to 0.03; P = .003), such that there was an inverse association only among those at a school with the mean environment score (adjusted β per 1% increase in single-parent households, -0.03; 95% CI, -0.05 to -0.01; P = .02) and worse (-1 SD score) school environment score (adjusted β per 1% increase in single-parent households, -0.05; 95% CI, -0.09 to -0.01; P < .001) but not among those at better (+1 SD score) school environments.

Conclusions and Relevance

In this study, an increased percentage of neighborhood-level single-parent households was associated with reduced right HV among children in schools with the mean or worse but not better environment score. These findings suggest that longitudinal research concerning the association of neighborhood-level characteristics and school environments with hippocampal development may be warranted to better understand complex interactions between various social factors and child neurodevelopment and mental health outcomes.

Faster pace of hippocampal growth mediates the association between perinatal adversity and childhood depression

Early life adversity has been posited to influence the pace of structural neurodevelopment. Most research, however, has relied on cross-sectional data, which do not reveal whether the pace of neurodevelopmental change is accelerated or slowed following early exposures. In a birth cohort study that included neuroimaging data obtained at 4.5, 6, and 7.5 years of age (N = 784), we examined associations among a cumulative measure of perinatal adversity relative to resources, nonlinear trajectories of hippocampal and amygdala volume, and children's subsequent depressive symptoms at 8.5 years of age. Greater adversity was associated with reduced bilateral hippocampal body volume in early childhood, but also to faster growth in the right hippocampal body across childhood. Further, the association between adversity and childhood depressive symptoms was mediated by faster hippocampal body growth. These findings suggest that perinatal adversity is biologically embedded in hippocampal structure development, including an accelerated pace of change in the right hippocampal body that is implicated in children's psychopathology risk. In addition, our findings suggest that reduced hippocampal volume is not inconsistent with accelerated hippocampal change; these aspects of structural development may typically co-occur, as smaller regional volumes in early childhood were associated with faster growth across childhood.

Disparate benefits of higher childhood socioeconomic status on cognition in young adulthood by intersectional social positions

OBJECTIVES

Emerging evidence supports the protective effects of higher childhood socioeconomic status (cSES) on cognition over the life course. However, less understood is if higher cSES confers benefits equally across intersecting social positions. Guided by a situational intersectionality perspective and the theory of Minority Diminished Returns (MDR), this study examined the extent to which associations between cSES and cognition in young adulthood are jointly moderated by racialized identity and region of childhood residence.

METHODS

Using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we used multilevel modeling to test associations between cSES and delayed recall and working memory 14 years later when participants were ages 25-34. Further, we examined the influence of racialized identity and region of childhood residence on these associations.

RESULTS

Higher cSES was associated with higher delayed recall and working memory scores across social positions. However, the strength of the association between higher cSES and working memory differed across racialized subgroups and region of childhood residence. We found a statistically significant three-way interaction between cSES, race and region of childhood residence. Of particular important, a small yet statistically robust association was found in all groups, but was especially strong among White Southerners and especially weak among Black participants from the South.

CONCLUSIONS

This study contributes to a growing body of research indicating that the protective effects of higher cSES on cognition are not universal across subgroups of intersecting social positions, consistent with the theory of MDR. These findings provide evidence for the importance of considering the role of systemic racism across geographic contexts as part of initiatives to promote equity in life course cognitive aging and brain health.

Functional brain connectivity predictors of prospective substance use initiation and their environmental correlates

Background

Early substance use initiation (SUI) places youth at substantially higher risk for later substance use disorders. Furthermore, adolescence is a critical period for the maturation of brain networks, the pace and magnitude of which are susceptible to environmental influences and may shape risk for SUI.

Methods

We examined whether patterns of functional brain connectivity during rest (rsFC), measured longitudinally in pre-and-early adolescence, can predict future SUI. In an independent sub-sample, we also tested whether these patterns are associated with key environmental factors, specifically neighborhood pollution and socioeconomic dimensions. We utilized data from the Adolescent Brain Cognitive Development (ABCD) Study®. SUI was defined as first-time use of at least one full dose of alcohol, nicotine, cannabis, or other drugs. We created a control group (N = 228) of participants without SUI who were matched with the SUI group (N = 233) on age, sex, race/ethnicity, and parental income and education.

Results

Multivariate analysis showed that whole-brain rsFC prior to SUI during 9-10 and 11-12 years of age successfully differentiated the prospective SUI and control groups. This rsFC signature was expressed more at older ages in both groups, suggesting a pattern of accelerated maturation in the SUI group in the years prior to SUI. In an independent sub-sample (N = 2,854) and adjusted for family socioeconomic factors, expression of this rsFC pattern was associated with higher pollution, but not neighborhood disadvantage.

Conclusion

Brain functional connectivity patterns in early adolescence that are linked to accelerated maturation and environmental exposures can predict future SUI in youth.

Experience-dependent neurodevelopment of self-regulation in adolescence

Adolescence is a period of rapid biobehavioral change, characterized in part by increased neural maturation and sensitivity to one's environment. In this review, we aim to demonstrate that self-regulation skills are tuned by adolescents' social, cultural, and socioeconomic contexts. We discuss adjacent literatures that demonstrate the importance of experience-dependent learning for adolescent development: environmental contextual influences and training paradigms that aim to improve regulation skills. We first highlight changes in prominent limbic and cortical regions-like the amygdala and medial prefrontal cortex-as well as structural and functional connectivity between these areas that are associated with adolescents' regulation skills. Next, we consider how puberty, the hallmark developmental milestone in adolescence, helps instantiate these biobehavioral adaptations. We then survey the existing literature demonstrating the ways in which cultural, socioeconomic, and interpersonal contexts drive behavioral and neural adaptation for self-regulation. Finally, we highlight promising results from regulation training paradigms that suggest training may be especially efficacious for adolescent samples. In our conclusion, we highlight some exciting frontiers in human self-regulation research as well as recommendations for improving the methodological implementation of developmental neuroimaging studies and training paradigms.

Psychopathology as long-term sequelae of maltreatment and socioeconomic disadvantage: Neurocognitive development perspectives

Neuroscience research underscores the critical impact of adverse experiences on brain development. Yet, there is limited understanding of the specific pathways linking adverse experiences to accelerated or delayed brain development and their ultimate contributions to psychopathology. Here, we present new longitudinal data demonstrating that neurocognitive functioning during adolescence, as affected by adverse experiences, predicts psychopathology during young adulthood. The sample included 167 participants (52% male) assessed in adolescence and young adulthood. Adverse experiences were measured by early maltreatment experiences and low family socioeconomic status. Cognitive control was assessed by neural activation and behavioral performance during the Multi-Source Interference Task. Psychopathology was measured by self-reported internalizing and externalizing symptomatology. Results indicated that higher maltreatment predicted heightened frontoparietal activation during cognitive control, indicating delayed neurodevelopment, which, in turn predicted higher internalizing and externalizing symptomatology. Furthermore, higher maltreatment predicted a steeper decline in frontoparietal activation across adolescence, indicating neural plasticity in cognitive control-related brain development, which was associated with lower internalizing symptomatology. Our results elucidate the crucial role of neurocognitive development in the processes linking adverse experiences and psychopathology. Implications of the findings and directions for future research on the effects of adverse experiences on brain development are discussed.

Experimental biology can inform our understanding of food insecurity

Food insecurity is a major public health issue. Millions of households worldwide have intermittent and unpredictable access to food and this experience is associated with greater risk for a host of negative health outcomes. While food insecurity is a contemporary concern, we can understand its effects better if we acknowledge that there are ancient biological programs that evolved to respond to the experience of food scarcity and uncertainty, and they may be particularly sensitive to food insecurity during development. Support for this conjecture comes from common findings in several recent animal studies that have modeled insecurity by manipulating predictability of food access in various ways. Using different experimental paradigms in different species, these studies have shown that experience of insecure access to food can lead to changes in weight, motivation and cognition. Some of these studies account for changes in weight through changes in metabolism, while others observe increases in feeding and motivation to work for food. It has been proposed that weight gain is an adaptive response to the experience of food insecurity as 'insurance' in an uncertain future, while changes in motivation and cognition may reflect strategic adjustments in foraging behavior. Animal studies also offer the opportunity to make in-depth controlled studies of mechanisms and behavior. So far, there is evidence that the experience of food insecurity can impact metabolic efficiency, reproductive capacity and dopamine neuron synapses. Further work on behavior, the central and peripheral nervous system, the gut and liver, along with variation in age of exposure, will be needed to better understand the full body impacts of food insecurity at different stages of development.

Lifestyle Factors Counteract the Neurodevelopmental Impact of Genetic Risk for Accelerated Brain Aging in Adolescence

BACKGROUND

The transition from childhood to adolescence is characterized by enhanced neural plasticity and a consequent susceptibility to both beneficial and adverse aspects of one's milieu.

METHODS

To understand the implications of the interplay between protective and risk-enhancing factors, we analyzed longitudinal data from the Adolescent Brain Cognitive Development (ABCD) Study (n = 834; 394 female). We probed the maturational correlates of positive lifestyle variables (friendships, parental warmth, school engagement, physical exercise, healthy nutrition) and genetic vulnerability to neuropsychiatric disorders (major depressive disorder, Alzheimer's disease, anxiety disorders, bipolar disorder, schizophrenia) and sought to further elucidate their implications for psychological well-being.

RESULTS

Genetic risk factors and lifestyle buffers showed divergent relationships with later attentional and interpersonal problems. These effects were mediated by distinguishable functional neurodevelopmental deviations spanning the limbic, default mode, visual, and control systems. More specifically, greater genetic vulnerability was associated with alterations in the normative maturation of areas rich in dopamine (D2), glutamate, and serotonin receptors and of areas with stronger expression of astrocytic and microglial genes, a molecular signature implicated in the brain disorders discussed here. Greater availability of lifestyle buffers predicted deviations in the normative functional development of higher density GABAergic (gamma-aminobutyric acidergic) receptor regions. The two profiles of neurodevelopmental alterations showed complementary roles in protection against psychopathology, which varied with environmental stress levels.

CONCLUSIONS

Our results underscore the importance of educational involvement and healthy nutrition in attenuating the neurodevelopmental sequelae of genetic risk factors. They also underscore the importance of characterizing early-life biomarkers associated with adult-onset pathologies.

Intrauterine Exposure to Antidepressants or Maternal Depressive Symptoms and Offspring Brain White Matter Trajectories From Late Childhood to Adolescence

BACKGROUND

During pregnancy, both selective serotonin reuptake inhibitor (SSRI) exposure and maternal depression have been associated with poor offspring neurodevelopmental outcomes. In a population-based cohort, we investigated the association between intrauterine exposure to SSRIs and depressive symptoms and offspring white matter development from childhood to adolescence.

METHODS

Self-reported SSRI use was verified by pharmacy records. In midpregnancy, women reported on depressive symptoms using the Brief Symptom Inventory. Using diffusion tensor imaging, offspring white matter microstructure, including whole-brain and tract-specific fractional anisotropy (FA) and mean diffusivity, was measured at 3 assessments between ages 7 to 15 years. The participants were divided into 4 groups: prenatal SSRI exposure (n = 37 with 60 scans), prenatal depression exposure (n = 229 with 367 scans), SSRI use before pregnancy (n = 72 with 95 scans), and reference (n = 2640 with 4030 scans).

RESULTS

Intrauterine exposure to SSRIs and depressive symptoms were associated with lower FA in the whole-brain and the forceps minor at 7 years. Exposure to higher prenatal depressive symptom scores was associated with lower FA in the uncinate fasciculus, cingulum bundle, superior and inferior longitudinal fasciculi, and corticospinal tracts. From ages 7 to 15 years, children exposed to prenatal depressive symptoms showed a faster increase in FA in these white matter tracts. Prenatal SSRI exposure was not related to white matter microstructure growth over and above exposure to depressive symptoms.

CONCLUSIONS

These results suggest that prenatal exposure to maternal depressive symptoms was negatively associated with white matter microstructure in childhood, but these differences attenuated during development, suggesting catch-up growth.

Genetic and brain similarity independently predict childhood anthropometrics and neighborhood socioeconomic conditions

Linking the developing brain with individual differences in clinical and demographic traits is challenging due to the substantial interindividual heterogeneity of brain anatomy and organization. Here we employ an integrative approach that parses individual differences in both cortical thickness and common genetic variants, and assess their effects on a wide set of childhood traits. The approach uses a linear mixed model framework to obtain the unique effects of each type of similarity, as well as their covariance. We employ this approach in a sample of 7760 unrelated children in the ABCD cohort baseline sample (mean age 9.9, 46.8% female). In general, associations between cortical thickness similarity and traits were limited to anthropometrics such as height, weight, and birth weight, as well as a marker of neighborhood socioeconomic conditions. Common genetic variants explained significant proportions of variance across nearly all included outcomes, although estimates were somewhat lower than previous reports. No significant covariance of the effects of genetic and cortical thickness similarity was found. The present findings highlight the connection between anthropometrics as well as neighborhood socioeconomic conditions and the developing brain, which appear to be independent from individual differences in common genetic variants in this population-based sample.

Neighborhood poverty during childhood prospectively predicts adolescent functional brain network architecture

Family poverty has been associated with altered brain structure, function, and connectivity in youth. However, few studies have examined how disadvantage within the broader neighborhood may influence functional brain network organization. The present study leveraged a longitudinal community sample of 538 twins living in low-income neighborhoods to evaluate the prospective association between exposure to neighborhood poverty during childhood (6-10 y) with functional network architecture during adolescence (8-19 y). Using resting-state and task-based fMRI, we generated two latent measures that captured intrinsic brain organization across the whole-brain and network levels - network segregation and network segregation-integration balance. While age was positively associated with network segregation and network balance overall across the sample, these associations were moderated by exposure to neighborhood poverty. Specifically, these positive associations were observed only in youth from more, but not less, disadvantaged neighborhoods. Moreover, greater exposure to neighborhood poverty predicted reduced network segregation and network balance in early, but not middle or late, adolescence. These effects were detected both across the whole-brain system as well as specific functional networks, including fronto-parietal, default mode, salience, and subcortical systems. These findings indicate that where children live may exert long-reaching effects on the organization and development of the adolescent brain.

Socioeconomic resources in youth are linked to divergent patterns of network integration and segregation across the brain's transmodal axis

Socioeconomic resources (SER) calibrate the developing brain to the current context, which can confer or attenuate risk for psychopathology across the lifespan. Recent multivariate work indicates that SER levels powerfully influence intrinsic functional connectivity patterns across the entire brain. Nevertheless, the neurobiological meaning of these widespread alterations remains poorly understood, despite its translational promise for early risk identification, targeted intervention, and policy reform. In the present study, we leverage the resources of graph theory to precisely characterize multivariate and univariate associations between household SER and the functional integration and segregation (i.e., participation coefficient, within-module degree) of brain regions across major cognitive, affective, and sensorimotor systems during the resting state in 5,821 youth (ages 9-10 years) from the Adolescent Brain Cognitive Development (ABCD) Study. First, we establish that decomposing the brain into profiles of integration and segregation captures more than half of the multivariate association between SER and functional connectivity with greater parsimony (100-fold reduction in number of features) and interpretability. Second, we show that the topological effects of SER are not uniform across the brain; rather, higher SER levels are related to greater integration of somatomotor and subcortical systems, but greater segregation of default mode, orbitofrontal, and cerebellar systems. Finally, we demonstrate that the effects of SER are spatially patterned along the unimodal-transmodal gradient of brain organization. These findings provide critical interpretive context for the established and widespread effects of SER on brain organization, indicating that SER levels differentially configure the intrinsic functional architecture of developing unimodal and transmodal systems. This study highlights both sensorimotor and higher-order networks that may serve as neural markers of environmental stress and opportunity, and which may guide efforts to scaffold healthy neurobehavioral development among disadvantaged communities of youth.

Family income is not significantly associated with T1w/T2w ratio in the Human Connectome Project in Development

Growing evidence indicates that brain development varies as a function of family socioeconomic status (SES). Numerous studies have demonstrated that children from low-SES backgrounds have thinner cortex than children from higher-SES backgrounds. A recent study in a large developmental sample found widespread associations between lower SES and greater cortical T1w/T2w ratio-thought to be an indirect proxy for cortical myelin. We evaluated the association of family income with cortical T1w/T2w ratio as a function of age in the Human Connectome Project in Development sample of 989 youth aged 8-21 years. We observed no associations between family income and T1w/T2w ratio that were significant after corrections for multiple comparisons at the region, network, or whole-brain level. Region of practical equivalence (ROPE) analyses were also consistent with the absence of an association between family income and T1w/T2w ratio. We discuss potential methodological sources of inconsistency between this and the previous study examining the same question. While the question of whether family income may influence cortical myelin development remains, these null results may indicate that the association between SES and cortical myelin development may not be as strong as with other aspects of brain structure.

Changes in the superior longitudinal fasciculus and anterior thalamic radiation in the left brain are associated with developmental dyscalculia

Developmental dyscalculia is a neurodevelopmental disorder specific to arithmetic learning even with normal intelligence and age-appropriate education. Difficulties often persist from childhood through adulthood lowering the individual's quality of life. However, the neural correlates of developmental dyscalculia are poorly understood. This study aimed to identify brain structural connectivity alterations in developmental dyscalculia. All participants were recruited from a large scale, non-referred population sample in a longitudinal design. We studied 10 children with developmental dyscalculia (11.3 ± 0.7 years) and 16 typically developing peers (11.2 ± 0.6 years) using diffusion-weighted magnetic resonance imaging. We assessed white matter microstructure with tract-based spatial statistics in regions-of-interest tracts that had previously been related to math ability in children. Then we used global probabilistic tractography for the first time to measure and compare tract length between developmental dyscalculia and typically developing groups. The high angular resolution diffusion-weighted magnetic resonance imaging and crossing-fiber probabilistic tractography allowed us to evaluate the length of the pathways compared to previous studies. The major findings of our study were reduced white matter coherence and shorter tract length of the left superior longitudinal/arcuate fasciculus and left anterior thalamic radiation in the developmental dyscalculia group. Furthermore, the lower white matter coherence and shorter pathways tended to be associated with the lower math performance. These results from the regional analyses indicate that learning, memory and language-related pathways in the left hemisphere might be related to developmental dyscalculia in children.

Prenatal environment is associated with the pace of cortical network development over the first three years of life

Environmental influences on brain structure and function during early development have been well-characterized. In pre-registered analyses, we test the theory that socioeconomic status (SES) is associated with differences in trajectories of intrinsic brain network development from birth to three years (n = 261). Prenatal SES is associated with developmental increases in cortical network segregation, with neonates and toddlers from lower-SES backgrounds showing a steeper increase in cortical network segregation with age, consistent with accelerated network development. Associations between SES and cortical network segregation occur at the local scale and conform to a sensorimotor-association hierarchy of cortical organization. SES-associated differences in cortical network segregation are associated with language abilities at two years, such that lower segregation is associated with improved language abilities. These results yield key insight into the timing and directionality of associations between the early environment and trajectories of cortical development.