State-level macro-economic factors moderate the association of low income with brain structure and mental health in U.S. children

Negative life events during early adolescence are associated with neural deactivation to emotional stimuli

Negative life events (NLEs) have been shown to perturb neurodevelopment and are correlated with poor mental health outcomes in adolescence, the most common period of psychopathology onset. Emotion regulation is a critical component of psychological response to NLEs and interacts, neurobiologically and behaviorally, with working memory. This study leveraged an emotional n-back task to examine how NLEs influence emotion- and working memory-related brain activation using data from 2150 youth in the Adolescent Brain Cognitive Development (ABCD) Study. Greater incidence of NLEs was associated with less activation in the amygdala and more pronounced deactivation in other limbic and frontal brain regions previously implicated in emotion-related cognition; however, this association was present only during emotion processing conditions of the task. While NLEs were not significantly associated with task performance in the final sample, behavioural analyses including youth excluded for low task accuracy and poor neuroimaging data quality showed a significant negative association between NLEs and overall task performance. While behavioural findings across the entire sample support prior work, somewhat incongruent with prior literature, imaging results may suggest that during early adolescence the effects of negative experiences on patterns of neural activation are specific to contexts necessitating emotion processing.

Debate: Urban versus rural environments - which is better for mental health? The one good thing about a small town…

Urban environments are related to higher prevalences of common mental disorders (addictions, anxieties and mood disorders) in adults. The mechanisms underlying this relationship are less clear. Cities function as a magnet, related to economic and educational opportunities, but are also related to urban stress and low well-being. Urban areas have larger inequalities, and people in deprived areas are at enhanced risk for mental health problems, which have been related both to environmental factors like pollution and to perceptions of the (social) environment, including perceived safety and social support. The interactions of vulnerability factors at different levels of description (e.g., within-person stress vulnerability vs. neighborhood stressors) can be considered a complex system. We here discuss what is known about growing up in an urban versus rural environment, with the aim to identify target points for mental health-related interventions in youth. We summarize this for three broad developmental periods: early life (first 1000 days), childhood, and adolescence into young adulthood, with implications for interventions.

Considerations When Accounting for Race and Ethnicity in Studies of Poverty and Neurodevelopment

OBJECTIVE

Poverty and systemic racism within rare intertwined. Children of marginalized racial and ethnic identities experience higher levels of poverty and adverse psychiatric outcomes. Thus, in models of poverty and neurodevelopment, race and ethnicity, as proxies for exposure to systemic disadvantage, are regularly considered confounders. Recently, however, some researchers have claimed that using race and ethnicity as confounders is statistically dubious, and potentially socially damaging. Instead, they argue for the use of variables measuring other social determinants of health (SDoH). We explore this approach herein.

METHOD

Data are from 7,836 children 10 years of age in the Adolescent Brain Cognitive Development Study (ABCD Study). We fit mixed regression models for the association of household poverty measures with psychiatric symptoms, magnetic resonance imaging (MRI)-derived cortical measures, and cognition with and without (1) race and ethnicity adjustment, (2) poverty-by-race and ethnicity interaction terms, and (3) alternative SDoH variables. Propensity-based weights were used to calibrate the sample to key US demographics.

RESULTS

For psychiatric and cognitive outcomes, poverty-outcome relationships differed across racial and ethnic groups (interaction of poverty by race and ethnicity, p < .05). For MRI-derived outcomes, adjusting for race and ethnicity changed the estimate of the impact of poverty. Alternative SDoH adjustment could not fully account for the impact of race and ethnicity on the associations explored.

CONCLUSION

Poverty and both race and ethnicity combine to influence neurodevelopment. Results suggest that the effects of poverty are generally inconsistent across race and ethnicity, which supports prior research demonstrating the nonequivalence of SDoH indicators by race and ethnicity. Studies exploring these relationships should assess the interaction between poverty and race and ethnicity and/or should stratify when appropriate. Replacing race and ethnicity with alternative SDoH may induce bias.

Unequal burdens: How structural socioeconomic inequality shapes brain health in aging and dementia

Structural socioeconomic inequality -the aggregate level unequal distribution of resources and opportunities within a region- significantly impacts brain health. Unlike traditional neuroscience approaches that focus on individual factors, recent studies highlight the biological embedding of macrosocial inequalities. We discuss studies on structural inequality that use EEG and f/MRI across diverse populations. Greater structural inequality is associated with adverse brain outcomes, such as reduced complexity, volume, and connectivity, particularly in temporo-posterior regions. Structural inequality significantly contributes to brain burden, even after accounting for individual demographics, and its effects are more pronounced in aging and dementia. This evidence opens a new framework for studying various physical (e.g., air pollution) and social (e.g., gender inequality, sociopolitical determinants) exposomes at the aggregate level in relation to brain health. Neuroscience can inform policymakers to address the positive brain health impacts of mitigating structural determinants of health through policies that enhance social safety and healthcare access.

Macropsychology: A Systematic Scoping Review of the Psychology Literature on Public Policy and Law

Macropsychology examines the influence of macro-level factors such as policies and laws on our psychological well-being and how the field of psychology can be more effectively leveraged to influence them. While psychology has traditionally been focused at the individual level, a greater focus is needed on policies and laws at the macro level, including areas that are underpinned by psychological concerns such as human rights and social justice. Systematic scoping review methods based on the PRISMA guidelines were used to examine the following research question: To what extent is psychology, through macropsychology, engaging with public policy and law, particularly in relation to social justice? In total, 118 articles were identified as meeting the inclusion criteria, including 46 empirical articles and 72 conceptual articles. Although the authors of such articles are clearly operating at the macro level, it is not evident that they conceptualise such work as macropsychology. This scoping review is the first to systematically synthesise psychological research at the macro level, adding value to the existing conceptualisation of macropsychology. This review calls attention to the work of psychologists engaging with public policy and law from a social justice perspective.

Opportunities and Needs to Advance Prevention of Substance Use Disorders

This Viewpoint discusses areas of opportunity for strengthening efforts to prevent substance use disorders among US youth.

Quantifying associations between socio-spatial factors and cognitive development in the ABCD cohort

Despite the mounting demand for generative population models, their limited generalizability to underrepresented demographic groups hinders widespread adoption in real-world applications. Here we propose a diversity-aware population modeling framework that can guide targeted strategies in public health and education, by estimating subgroup-level effects and stratifying predictions to capture sociodemographic variability. We leverage Bayesian multilevel regression and post-stratification to systematically quantify inter-individual differences in the relationship between socioeconomic status and cognitive development. Post-stratification enhanced the interpretability of model predictions across underrepresented groups by incorporating US Census data to gain additional insights into smaller subgroups in the Adolescent Brain Cognitive Development Study. This ensured that predictions were not skewed by overly heterogeneous or homogeneous representations. Our analyses underscore the importance of combining Bayesian multilevel modeling with post-stratification to validate reliability and provide a more holistic explanation of sociodemographic disparities in our diversity-aware population modeling framework.

The Role of Social Determinants in Racial and Ethnic Mental Health Disparities: Getting It Right

ABSTRACT

Despite increased research on and attention to mental health, significant racial and ethnic disparities in this area persist. We propose that racial and ethnic disparities in mental health should be examined through the lens of social determinants of mental health (SDoMH). In this perspective article, we review current definitions and frameworks of SDoMH, discuss their strengths and shortcomings, and provide recommendations for a framework to better capture the causal pathways of mental health for racially and ethnically minoritized populations. We also discuss efforts to address SDoMH, focusing on policy-level SDoMH interventions, and review progress and challenges in integrating SDoMH approaches into mental health care.

Air pollution and cortical myelin T1w/T2w ratio estimates in school-age children from the ABCD and NeuroSmog studies

Air pollution affects human health and may disrupt brain maturation, including axon myelination, critical for efficient neural signaling. Here, we assess the impact of prenatal and current long-term particulate matter (PM) and nitrogen dioxide (NO2) exposure on cortical T1w/T2w ratios - a proxy for myelin content - in school-age children from the Adolescent Brain Cognitive Development (ABCD) Study (United States; N = 2021) and NeuroSmog study (Poland; N = 577), using Siemens scanners. Across both samples, we found that NO2 and PM were not significantly associated with cortical T1w/T2w except for one association of PM10 with lower T1w/T2w in the precuneus in NeuroSmog. Superficially, ABCD Study analyses including data from all scanner types (Siemens, GE, Philips; N = 3089) revealed a negative association between NO₂ exposure and T1w/T2w ratios. However, this finding could be an artifact of between-site sociodemographic differences and large scanner-type-related measurement differences. While significant associations between air pollution and cortical myelin were largely absent, these findings do not rule out the possibility that air pollution affects cortical myelin during other exposure periods/stages of neurodevelopment. Future research should examine these relationships across diverse populations and developmental periods using unified analysis methods to better understand the potential neurotoxic effects of air pollution.

Structural inequality linked to brain volume and network dynamics in aging and dementia across the Americas

Structural inequality, the uneven distribution of resources and opportunities, influences health outcomes. However, the biological embedding of structural inequality in aging and dementia, especially among underrepresented populations, is unclear. We examined the association between structural inequality (country-level and state-level Gini indices) and brain volume and connectivity in 2,135 healthy controls, and individuals with Alzheimer's disease and frontotemporal lobe degeneration from Latin America and the United States. Greater structural inequality was linked to reduced brain volume and connectivity, with stronger effects in Latin America, especially in the temporo-cerebellar, fronto-thalamic and hippocampal regions. In the United States, milder effects were observed in the insular-cingular and temporal areas. Results were more pronounced in Alzheimer's disease and were independent of age, sex, education, cognition and other confounding factors. The findings highlight the critical role of structural inequality in aging and dementia, emphasizing the biological embedding of macrosocial factors and the need for targeted interventions in underserved populations.

Pre-COVID respiratory sinus arrhythmia moderates associations between COVID-19 stress and child externalizing behaviors: Testing neurobiological stress theories

Exposure to stress related to the COVID-19 pandemic contributes to psychopathology risk, yet not all children are negatively impacted. The current study examined a parasympathetic biomarker of stress sensitivity, respiratory sinus arrhythmia (RSA), as a moderator of the effects of exposure to pandemic stress on child internalizing and externalizing behaviors in a sample of children experiencing economic marginalization. Three to five years pre-pandemic, when children were preschool-aged, RSA during baseline and a challenging parent-child interaction were collected. Mid-pandemic, between November 2020 and March 2021, children's exposure to pandemic stress and internalizing and externalizing behaviors were collected. Results demonstrated that children who, pre-pandemic, demonstrated blunted parasympathetic reactivity (i.e., no change in RSA relative to baseline) during the dyadic challenge exhibited elevated risk for externalizing behaviors mid-pandemic. Further, this risk was greatest for children exposed to high and moderate levels of pandemic stress. Consistent with diathesis stress and polyvagal frameworks, these conditional effects suggest that blunted parasympathetic reactivity in response to stress in early childhood may escalate the development of externalizing behaviors following stress exposure at school age.

The connecting brain in context: How adolescent plasticity supports learning and development

Puberty initiates significant neurobiological changes that amplify adolescents' responsiveness to their environment, facilitating neural adaptation through processes like synaptic pruning, myelination, and neuronal reorganization. This heightened neuroplasticity, combined with their burgeoning social curiosity and appetite for risk, propels adolescents to explore diverse new environments and forge social bonds. Such exploration can accelerate experiential learning and the formation of social networks as adolescents prepare for adult independence. This review examines the complex interplay between adolescent neuroplasticity, environmental influences, and learning processes, synthesizing findings from recent studies that illustrate how factors such as social interactions, school environments, and neighborhood contexts influence both the transient activation and enduring organization of the developing brain. We advocate for incorporating social interaction into adolescent-tailored interventions, leveraging their social plasticity to optimize learning and development during this critical phase. Going forward, we discuss the importance of longitudinal studies that employ multimodal approaches to characterize the dynamic interactions between development and environment, highlighting recent advancements in quantifying environmental impacts in studies of developmental neuroscience. Ultimately, this paper provides an updated synopsis of adolescent neuroplasticity and the environment, underscoring the potential for environmental enrichment programs to support healthy brain development and resilience at this critical development stage.

Gender diversity and daily steps: Findings from the Adolescent Brain Cognitive Development Study

PURPOSE

To examine the association between multiple dimensions of gender diversity and physical activity (daily steps) in a diverse national sample of early adolescents in the United States.

METHODS

This study analyzed Year 2 data from the Adolescent Brain Cognitive Development (ABCD) Study (N = 6038, Mage=12.0 years). Linear regression models were used to estimate the associations of gender diversity across multiple measures (transgender identity, felt gender, gender expression, gender non-contentedness) with daily step count measured by wrist-worn Fitbit devices.

RESULTS

In this sample of early adolescents, 49.7 % were assigned female at birth, 39.4 % were from racial/ethnic minority groups, and 1 % to 16.9 % identified as gender diverse, depending on the measure used. Transgender identity was associated with 1394 (95 % confidence interval 284-2504) fewer steps per day compared to cisgender identity after adjusting for all covariates. Greater gender diversity, as measured by felt gender and gender non-contentedness, was also associated with lower daily steps.

CONCLUSIONS

Transgender and gender-diverse adolescents engage in less physical activity than their cisgender peers. This research has important implications for public health and policies focused on supporting physical activity among transgender and gender-diverse early adolescents.

Perspectives on Integrating Biological Assessments to Address the Health Effects of Childhood Adversities

ABSTRACT

A majority of adults in the United States (US) report a range of stressful and potentially traumatic childhood experiences (e.g., physical or sexual abuse, witnessing violence, neglect). Such adversities are associated with a range of mental (e.g., anxiety, mood, and behavioral difficulties) and physical (e.g., cardiovascular illnesses, diabetes, asthma) health problems. Increasingly, precision medicine approaches seek to prevent and treat such multifinal downstream health problems by identifying common etiological pathways (e.g., inflammation and immune pathways) and candidate biomarkers to target interventions. In this context, we review the rationale for continued research to identify biomarkers of childhood adversity. Building on the bioecological theory, we emphasize that individual neurobiological profiles develop within multiple ecological levels (individual, family, neighborhood, macrosocial) that confer both risk and protective factors that can attenuate or amplify biological effects of childhood adversity. Given the limited data on adversity-associated biomarkers for children and adolescents, we discuss future recommendations for research, implications for clinical care, and ethical considerations. Preventing childhood adversity and supporting adversity- and trauma-informed systemic intervention approaches remains our primary recommendation. We highlight the continued need to consider both biomarkers of risk and protective factors across ecological levels in future research.

Brain structures with stronger genetic associations are not less associated with family- and state-level economic contexts

We investigate whether neural, cognitive, and psychopathology phenotypes that are more strongly related to genetic differences are less strongly associated with family- and state-level economic contexts (N = 5374 individuals with 1KG-EUR-like genotypes with 870 twins, from the Adolescent Behavior and Cognitive Development study). We estimated the twin- and SNP-based heritability of each phenotype, as well as its association with an educational attainment polygenic index (EA PGI). We further examined associations with family socioeconomic status (SES) and tested whether SES-related differences were moderated by state cost of living and social safety net programs (Medicaid expansion and cash assistance). SES was broadly associated with cognition, psychopathology, brain volumes, and cortical surface areas, even after controlling for the EA PGI. Brain phenotypes that were more heritable or more strongly associated with the EA PGI were not, overall, less related to SES, nor were SES-related differences in these phenotypes less moderated by macroeconomic context and policy. Informing a long-running theoretical debate, and contra to widespread lay beliefs, results suggest that aspects of child brain development that are more strongly related to genetic differences are not, in general, less associated with socioeconomic contexts and policies.

The Promise and Challenges of Integrating Biological and Prevention Sciences: A Community-Engaged Model for the Next Generation of Translational Research

Beginning with the successful sequencing of the human genome two decades ago, the possibility of developing personalized health interventions based on one's biology has captured the imagination of researchers, medical providers, and individuals seeking health care services. However, the application of a personalized medicine approach to emotional and behavioral health has lagged behind the development of personalized approaches for physical health conditions. There is potential value in developing improved methods for integrating biological science with prevention science to identify risk and protective mechanisms that have biological underpinnings, and then applying that knowledge to inform prevention and intervention services for emotional and behavioral health. This report represents the work of a task force appointed by the Board of the Society for Prevention Research to explore challenges and recommendations for the integration of biological and prevention sciences. We present the state of the science and barriers to progress in integrating the two approaches, followed by recommended strategies that would promote the responsible integration of biological and prevention sciences. Recommendations are grounded in Community-Based Participatory Research approaches, with the goal of centering equity in future research aimed at integrating the two disciplines to ultimately improve the well-being of those who have disproportionately experienced or are at risk for experiencing emotional and behavioral problems.

The next generation of developmental psychopathology research: Including broader perspectives and becoming more precise

The current Special Issue marks a major milestone in the history of developmental psychopathology; as the final issue edited by Cicchetti, we have an opportunity to reflect on the remarkable progress of the discipline across the last four decades, as well as challenges and future directions for the field. With contemporary issues in mind, including rising rates of psychopathology, health disparities, and international conflict, as well as rapid growth and accessibility of digital and mobile technologies, the discipline of developmental psychopathology is poised to advance multidisciplinary, developmentally- and contextually- informed research, and to make substantial progress in supporting the healthy development of individuals around the world. We highlight key future directions and challenges for the next generation of developmental psychopathology research including further investigation of culture at multiple levels of analysis, incorporation of macro-level influences into developmental psychopathology research, methods advances to address heterogeneity in translational research, precision mental health, and the extension of developmental psychopathology research across the lifespan.

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.

Correlation analysis of exercise volume and musculoskeletal disorders in people with income level differences: research based on the 2011-2018 NHANES dataset

OBJECTIVES

Socioeconomic factors significantly impact human health; however, the impact of exercise and income on musculoskeletal system health remains unclear. Our study aims to explore the relationship between exercise and income with musculoskeletal system health in young and middle-aged adults.

DESIGN

This cross-sectional study used data from 7,515 adults aged 20-59 years, which were obtained from the US NHANES, 2011-2018. Participants' musculoskeletal system health was evaluated on the basis of them having osteopenia, osteoporosis, or sarcopenia.

METHODS

Ordinal regression was used to explore the correlation between income level, exercise volume, and musculoskeletal system health. Mediating effect analysis was used to assess whether the exercise volume affected the impact of income levels on musculoskeletal system health. Ordinal regression and restricted cubic spline curve were used to further analyze the relationship between exercise and income level.

RESULTS

In the analysis of adjusted all covariates, the probability of having good musculoskeletal system health in high-income participants was higher than that of low- or middle-income participants. The probability of having good musculoskeletal system health in the actively exercising group higher than that of the participants exercised insufficiently or sufficiently. Mediating effect of exercise masked the effect of income on musculoskeletal system health. Participants with low income levels tended to spend more time exercising that those who had high income levels; exercise volume and income level had a significant non-linear relationship.

CONCLUSION

The findings presented will help identify young and middle-aged adults who are most at risk of developing musculoskeletal health problem and will likely benefit from certain lifestyle interventions.

Structural inequality and temporal brain dynamics across diverse samples

BACKGROUND

Structural income inequality - the uneven income distribution across regions or countries - could affect brain structure and function, beyond individual differences. However, the impact of structural income inequality on the brain dynamics and the roles of demographics and cognition in these associations remains unexplored.

METHODS

Here, we assessed the impact of structural income inequality, as measured by the Gini coefficient on multiple EEG metrics, while considering the subject-level effects of demographic (age, sex, education) and cognitive factors. Resting-state EEG signals were collected from a diverse sample (countries = 10; healthy individuals = 1394 from Argentina, Brazil, Colombia, Chile, Cuba, Greece, Ireland, Italy, Turkey and United Kingdom). Complexity (fractal dimension, permutation entropy, Wiener entropy, spectral structure variability), power spectral and aperiodic components (1/f slope, knee, offset), as well as graph-theoretic measures were analysed.

FINDINGS

Despite variability in samples, data collection methods, and EEG acquisition parameters, structural inequality systematically predicted electrophysiological brain dynamics, proving to be a more crucial determinant of brain dynamics than individual-level factors. Complexity and aperiodic activity metrics captured better the effects of structural inequality on brain function. Following inequality, age and cognition emerged as the most influential predictors. The overall results provided convergent multimodal metrics of biologic embedding of structural income inequality characterised by less complex signals, increased random asynchronous neural activity, and reduced alpha and beta power, particularly over temporoposterior regions.

CONCLUSION

These findings might challenge conventional neuroscience approaches that tend to overemphasise the influence of individual-level factors, while neglecting structural factors. Results pave the way for neuroscience-informed public policies aimed at tackling structural inequalities in diverse populations.

The ABCD and HBCD Studies: Longitudinal Studies to Inform Prevention Science

Increasing rates of overdose among U.S. adolescents and young adults, along with rising rates of emotional distress in these groups, are renewing the urgency for developmentally targeted and personalized substance use and other mental health prevention interventions. Most prevention programs recognize the unique vulnerability of childhood and adolescence and target parents and youths, addressing modifiable environmental risk and protective factors that affect behavior during periods when the brain is most susceptible to change. Until recently, a scarcity of comprehensive studies has limited a full understanding of the complexity of factors that may affect neurodevelopment, including substance exposure in pregnancy and/or subsequent substance use in adolescence, alongside their dynamic interactions with environmental factors and genetics. Two large longitudinal cohort studies funded by National Institutes of Health-the Adolescent Brain Cognitive Development (ABCD) Study and the HEALthy Brain and Child Development (HBCD) Study-are collecting data on neurodevelopment and a wide range of environmental and biological factors across the first two decades of life to build databases that will allow researchers to study how individual neurodevelopmental trajectories are influenced by drugs, adverse childhood experiences, and genetics, among other factors. These studies are already deepening the understanding of risk and resilience factors that prevention programs could target and will identify critical windows where interventions can have the most impact on an individual's neurodevelopmental trajectory. This article describes what is being learned from ABCD and expected from HBCD and how these studies might inform prevention as these children grow and more data are gathered.

Systematic Review of the Impacts of U.S. Social Safety Nets on Child Maltreatment

INTRODUCTION

Children living in poverty are at an increased risk for maltreatment. Social safety net (SSN) programs with antipoverty objectives may reduce child maltreatment through pathways such as reduced food insecurity, lessened caregiver stress, and improved caregiving behaviors and ability to meet children's basic needs. The objective of this study is to conduct a systematic review of evidence on the ability of SSN programs to reduce child maltreatment in the United States (U.S.).

METHODS

This systematic review was conducted using PRISMA protocol. Among studies published between 1996-2022, the initial search returned 1,873 articles, and 27 papers were included in the final analysis. Abstracts were identified primarily on June 24th, 2022, and extraction and synthesis of data was conducted in 2022-2023.

RESULTS

Of the 27 papers assessed, 16 studies found that SSN programs were protective against child maltreatment. Three of the reviewed studies found no effect of safety net programs, 4 studies presented mixed findings, and 4 studies found adverse impacts in terms of child maltreatment outcomes. When restricting to high-quality studies only, 10 out of 12 found protective impacts and none found adverse impacts on child maltreatment.

DISCUSSION

SSNs are associated with protective effects against child maltreatment. Expansion of SSN programs would likely have positive benefits beyond poverty-related objectives, including reducing incidence of child maltreatment.

The impact of poverty and socioeconomic status on brain, behaviour, and development: a unified framework

In this article, we, for the first time, provide a comprehensive overview and unified framework of the impact of poverty and low socioeconomic status (SES) on the brain and behaviour. While there are many studies on the impact of low SES on the brain (including cortex, hippocampus, amygdala, and even neurotransmitters) and behaviours (including educational attainment, language development, development of psychopathological disorders), prior studies did not integrate behavioural, educational, and neural findings in one framework. Here, we argue that the impact of poverty and low SES on the brain and behaviour are interrelated. Specifically, based on prior studies, due to a lack of resources, poverty and low SES are associated with poor nutrition, high levels of stress in caregivers and their children, and exposure to socio-environmental hazards. These psychological and physical injuries impact the normal development of several brain areas and neurotransmitters. Impaired functioning of the amygdala can lead to the development of psychopathological disorders, while impaired hippocampus and cortex functions are associated with a delay in learning and language development as well as poor academic performance. This in turn perpetuates poverty in children, leading to a vicious cycle of poverty and psychological/physical impairments. In addition to providing economic aid to economically disadvantaged families, interventions should aim to tackle neural abnormalities caused by poverty and low SES in early childhood. Importantly, acknowledging brain abnormalities due to poverty in early childhood can help increase economic equity. In the current study, we provide a comprehensive list of future studies to help understand the impact of poverty on the brain.

Integrating developmental neuroscience with community-engaged approaches to address mental health outcomes for housing-insecure youth: Implications for research, practice, and policy

One in three children in the United States is exposed to insecure housing conditions, including unaffordable, inconsistent, and unsafe housing. These exposures have detrimental impacts on youth mental health. Delineating the neurobehavioral pathways linking exposure to housing insecurity with children's mental health has the potential to inform interventions and policy. However, in approaching this work, carefully considering the lived experiences of youth and families is essential to translating scientific discovery to improve health outcomes in an equitable and representative way. In the current paper, we provide an introduction to the range of stressful experiences that children may face when exposed to insecure housing conditions. Next, we highlight findings from the early-life stress literature regarding the potential neurobehavioral consequences of insecure housing, focusing on how unpredictability is associated with the neural circuitry supporting cognitive and emotional development. We then delineate how community-engaged research (CEnR) approaches have been leveraged to understand the effects of housing insecurity on mental health, and we propose future research directions that integrate developmental neuroscience research and CEnR approaches to maximize the impact of this work. We conclude by outlining practice and policy recommendations that aim to improve the mental health of children exposed to insecure housing.

Diversity-aware Population Models: Quantifying Associations between Socio-Spatial Factors and Cognitive Development in the ABCD Cohort

Population-level analyses are inherently complex due to a myriad of latent confounding effects that underlie the interdisciplinary topics of research interest. Despite the mounting demand for generative population models, the limited generalizability to underrepresented groups hinders their widespread adoption in downstream applications. Interpretability and reliability are essential for clinicians and policymakers, while accuracy and precision are prioritized from an engineering standpoint. Thus, in domains such as population neuroscience, the challenge lies in determining a suitable approach to model population data effectively. Notably, the traditional strata-agnostic nature of existing methods in this field reveals a pertinent gap in quantitative techniques that directly capture major sources of population stratification. The emergence of population-scale cohorts, like the Adolescent Brain Cognitive DevelopmentSM (ABCD) Study, provides unparalleled opportunities to explore and characterize neurobehavioral and sociodemographic relationships comprehensively. We propose diversity-aware population modeling, a framework poised to standardize systematic incorporation of diverse attributes, structured with respect to intrinsic population stratification to obtain holistic insights. Here, we leverage Bayesian multilevel regression and poststratification, to elucidate inter-individual differences in the relationships between socioeconomic status (SES) and cognitive development. We constructed 14 varying-intercepts and varying-slopes models to investigate 3 cognitive phenotypes and 5 sociodemographic variables (SDV), across 17 US states and 5 race subgroups. SDVs exhibited systemic socio-spatial effects that served as fundamental drivers of variation in cognitive outcomes. Low SES was disproportionately associated with cognitive development among Black and Hispanic children, while high SES was a robust predictor of cognitive development only among White and Asian children, consistent with the minorities' diminished returns (MDRs) theory. Notably, adversity-susceptible subgroups demonstrated an expressive association with fluid cognition compared to crystallized cognition. Poststratification proved effective in correcting group attribution biases, particularly in Pennsylvania, highlighting sampling discrepancies in US states with the highest percentage of marginalized participants in the ABCD Study©. Our collective analyses underscore the inextricable link between race and geographic location within the US. We emphasize the importance of diversity-aware population models that consider the intersectional composition of society to derive precise and interpretable insights across applicable domains.

Socioeconomic Status Partially Mediates the Effects of Structural Racism on Youth Tobacco Use Initiation

Background

Recent research has identified structural racism-systemic policies and practices that perpetuate racial inequalities-as a significant social determinant of population health. Studies utilizing data from the Adolescent Brain Cognitive Development (ABCD) study have shown an association between higher levels of state-level structural racism and increased tobacco use among youth in the United States. However, there has been limited exploration of the psychosocial mediators of this relationship, particularly in the context of youth aged 10-16 years.

Objective

This study aimed to assess the roles of socioeconomic status (SES), tobacco susceptibility, and perceived discrimination as potential mediators in the relationship between state-level structural racism and youth tobacco initiation rates.

Methods

We analyzed data from the ABCD study, a nationally representative longitudinal survey of 11,698 youth followed from ages 9/10 to 15/16. These data were combined with state-level indicators of structural racism. We employed structural equation modeling (SEM) to investigate the mediators of the association between structural racism and self-reported initiation of tobacco use, while controlling for individual and state-level covariates.

Results

Our findings indicate that higher levels of structural racism were associated with increased rates of tobacco initiation among youth. This relationship was partially mediated by lower SES, but not by perceived discrimination or tobacco susceptibility.

Conclusion

The association between structural racism and youth tobacco initiation appears to be influenced in part by the lower SES prevalent in states with higher levels of racism. These results highlight the need for addressing both racism and SES inequalities as key strategies for reducing tobacco disparities among youth.

Childhood obesity's effect on cognition and brain connectivity worsens with low family income

Childhood obesity and its adverse health consequences have risen worldwide, with low socioeconomic status increasing the risk in high-income countries like the United States. Understanding the interplay between childhood obesity, cognition, socioeconomic factors, and the brain is crucial for prevention and treatment. Using data from the Adolescent Brain Cognitive Development (ABCD) study, we investigated how body mass index (BMI) relates to brain structural and functional connectivity metrics. Children with obesity or who are overweight (n = 2,356) were more likely to live in poverty and exhibited lower cognitive performance compared with children with a healthy weight (n = 4,754). Higher BMI was associated with multiple brain measures that were strongest for lower longitudinal diffusivity in corpus callosum; increased activity in cerebellum, insula, and somatomotor cortex; and decreased functional connectivity in multimodal brain areas, with effects more pronounced among children from low-income families. Notably, nearly 80% of the association of low income and 70% of the association of impaired cognition on BMI were mediated by higher brain activity in somatomotor areas. Increased resting activity in somatomotor areas and decreased structural and functional connectivity likely contribute to the higher risk of being overweight or having obesity among children from low-income families. Supporting low-income families and implementing educational interventions to improve cognition may promote healthy brain function and reduce the risk of obesity.

Differences in educational opportunity predict white matter development

Coarse measures of socioeconomic status, such as parental income or parental education, have been linked to differences in white matter development. However, these measures do not provide insight into specific aspects of an individual's environment and how they relate to brain development. On the other hand, educational intervention studies have shown that changes in an individual's educational context can drive measurable changes in their white matter. These studies, however, rarely consider socioeconomic factors in their results. In the present study, we examined the unique relationship between educational opportunity and white matter development, when controlling other known socioeconomic factors. To explore this question, we leveraged the rich demographic and neuroimaging data available in the ABCD study, as well the unique data-crosswalk between ABCD and the Stanford Education Data Archive (SEDA). We find that educational opportunity is related to accelerated white matter development, even when accounting for other socioeconomic factors, and that this relationship is most pronounced in white matter tracts associated with academic skills. These results suggest that the school a child attends has a measurable relationship with brain development for years to come.

Lifespan Socioeconomic Context Is Associated With Cytomegalovirus and Late-Differentiated CD8 + T and Natural Killer Cells: Initial Results in Older Adults

OBJECTIVE

Lower socioeconomic status (SES) can accelerate immune aging; however, it is unknown whether and how lifespan socioeconomic context (SEC)-the relative wealth and quality of the communities an individual lives in across their lifespan-impacts immune aging. We examined the effects of childhood and adulthood SEC on late-differentiated immune cells and investigated the mediating and moderating role of cytomegalovirus (CMV), a key driver of immune aging.

METHODS

Adults 60 years and older ( N = 109) reported their addresses from birth to age 60 years, which were coded for county-level employment, education, and income to construct a latent SEC variable, averaged across ages 0 to 18 years (childhood SEC) and 19 to 60 years (adulthood SEC). Blood was drawn semiannually for 5 years for CMV serostatus and flow cytometry estimates of late-differentiated CD8 + T and natural killer cells. Models were adjusted for chronological age, time, sex, and individual SES (current income and education).

RESULTS

Lower childhood SEC was associated with higher percentages of late-differentiated CD8 + T and natural killer cells via CMV seropositivity (indirect effects, p values = .015-.028). In addition, an interaction between CMV serostatus and SEC on CD8 + T-cell aging ( p = .049) demonstrated that adulthood SEC was negatively associated with immune aging among CMV- but not CMV+ adults.

CONCLUSIONS

Beyond current SES, SEC related to immune aging in distinct patterns by lifespan phase. Lower childhood SEC importantly may influence who acquires CMV, which in turn predicts higher levels of immune aging, whereas higher adulthood SEC was protective against immune aging among CMV- older adults. These initial results need to be explored in larger samples.

Current perspectives on perinatal mental health and neurobehavioral development: focus on regulation, coregulation and self-regulation

PURPOSE OF REVIEW

Perinatal mental health research provides an important perspective on neurobehavioral development. Here, we aim to review the association of maternal perinatal health with offspring neurodevelopment, providing an update on (self-)regulation problems, hypothesized mechanistic pathways, progress and challenges, and implications for mental health.

RECENT FINDINGS

(1) Meta-analyses confirm that maternal perinatal mental distress is associated with (self-)regulation problems which constitute cognitive, behavioral, and affective social-emotional problems, while exposure to positive parental mental health has a positive impact. However, effect sizes are small. (2) Hypothesized mechanistic pathways underlying this association are complex. Interactive and compensatory mechanisms across developmental time are neglected topics. (3) Progress has been made in multiexposure studies. However, challenges remain and these are shared by clinical, translational and public health sciences. (4) From a mental healthcare perspective, a multidisciplinary and system level approach employing developmentally-sensitive measures and timely treatment of (self-)regulation and coregulation problems in a dyadic caregiver-child and family level approach seems needed. The existing evidence-base is sparse.

SUMMARY

During the perinatal period, addressing vulnerable contexts and building resilient systems may promote neurobehavioral development. A pluralistic approach to research, taking a multidisciplinary approach to theoretical models and empirical investigation needs to be fostered.

Genetic variation in endocannabinoid signaling: Anxiety, depression, and threat- and reward-related brain functioning during the transition into adolescence

BACKGROUND

The endocannabinoid system modulates neural activity throughout the lifespan. In adults, neuroimaging studies link a common genetic variant in fatty acid amide hydrolase (FAAH C385A)-an enzyme that regulates endocannabinoid signaling-to reduced risk of anxiety and depression, and altered threat- and reward-related neural activity. However, limited research has investigated these associations during the transition into adolescence, a period of substantial neurodevelopment and increased psychopathology risk.

METHODS

This study included FAAH genotype and longitudinal neuroimaging and neurobehavioral data from 4811 youth (46% female; 9-11 years at Baseline, 11-13 years at Year 2) from the Adolescent Brain Cognitive DevelopmentSM Study. Linear mixed models examined the effects of FAAH and the FAAH x time interaction on anxiety and depressive symptoms, amygdala reactivity to threatening faces, and nucleus accumbens (NAcc) response to happy faces during the emotional n-back task.

RESULTS

A significant main effect of FAAH on depressive symptoms was observed, such that depressive symptoms were lower across both timepoints in those with the AA genotype compared to both AC and CC genotypes (p's<0.05). There were no significant FAAH x time interactions for anxiety, depression, or neural responses (p's>0.05). Additionally, there were no main effects of FAAH on anxiety or neural responses (p's>0.05).

CONCLUSIONS

Our findings add to emerging evidence linking the FAAH C385A variant to lower risk of psychopathology, and extend these findings to a developmental sample. In particular, we found lower depressive symptoms in FAAH AA genotypes compared to AC and CC genotypes. Future research is needed to characterize the role of the FAAH variant and the eCB system more broadly in neurodevelopment and psychiatric risk.

Psychological and Physiological Stress and Stressors in Early Childhood Educators: An Observational Pilot Study

While early childhood educators' mental health is important, it may also affect the well-being and education of their students. Yet, little research has described the stress and stressors of early childhood educators (ECEs), particularly as the pandemic wanes. This pilot study aimed to (1) describe ECEs' psychological and physiological stress and (2) examine the association between ECEs' psychological and physiological stress levels with stressors. A convenience sample of 67 ECEs, serving children 0-5 years old from 13 early educational centers completed surveys on psychological stress (perceived stress, anxiety, and depression), stressors (economic hardship, food insecurity, adverse childhood experiences), and demographics in Fall 2021. A subsample of ECEs provided hair samples, analyzed for cortisol, to estimate physiologic stress. Regarding stress, 63% met the criteria for major depressive disorder and 41% for generalized anxiety disorder. Only 26% were taking medications to manage mental health. About 25% experienced the stressors of food insecurity and economic hardship; 80% experienced at least one adverse childhood experience. Only education level significantly predicted perceived stress and depression - above and beyond stressors, household income, race, and age. The results have policy and practice implications for implementing evidence-based solutions to buffer stress and stressors in early childhood educators.

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.

State-Level Safety Net Spending and Educational Gaps in Maternal Time with Children

Objective

We examine how state spending on children is associated with the size of socioeconomic gaps in maternal childcare time.

Background

Persistent socioeconomic divides in the amount and nature of parental time with children have prompted consideration of the factors that mitigate inequalities within the family. At both the national and local levels, the welfare state plays an important role in structuring opportunities for children. Thus it is important to understand the institutional factors that shape parental behavior. Yet, little research examines how the social safety net is associated with family processes.

Method

Using rich data on maternal time with children from the American Time Use Surveys (2003-2016), combined with longitudinal data on public spending in states on major programs affecting children and families, we examine how state spending on children is associated with the size of socioeconomic gaps in maternal childcare time.

Results

We found that higher levels of state spending were associated with significant increases in childcare time among low-educated mothers at both the extensive and intensive margin, increasing the likelihood of spending any minutes on primary childcare in a typical day, as well as increasing the number of minutes spent on childcare. In contrast, we observed no variation in the behavior of highly-educated mothers as state spending changes.

Implications

State-level investments could meaningfully narrow socioeconomic gaps in maternal time with children.

Traumatic brain injury, working memory-related neural processing, and alcohol experimentation behaviors in youth from the ABCD cohort

Adolescent traumatic brain injury (TBI) has long-term effects on brain functioning and behavior, impacting neural activity under cognitive load, especially in the reward network. Adolescent TBI is also linked to risk-taking behaviors including alcohol misuse. It remains unclear how TBI and neural functioning interact to predict alcohol experimentation during adolescence. Using Adolescent Brain Cognitive Development (ABCD) study data, this project examined if TBI at ages 9-10 predicts increased odds of alcohol sipping at ages 11-13 and if this association is moderated by neural activity during the Emotional EN-Back working memory task at ages 11-13. Logistic regression analyses showed that neural activity in regions of the fronto-basal ganglia network predicted increased odds of sipping alcohol by ages 11-13 (p < .05). TBI and left frontal pole activity interacted to predict alcohol sipping (OR = 0.507, 95% CI [0.303 - 0.846], p = .009) - increased activity predicted decreased odds of alcohol sipping for those with a TBI (OR = 0.516, 95% CI [0.314 - 0.850], p = .009), but not for those without (OR = 0.971, 95% CI [0.931 -1.012], p = .159). These findings suggest that for youth with a TBI, increased BOLD activity in the frontal pole, underlying working memory, may be uniquely protective against the early initiation of alcohol experimentation. Future work will examine TBI and alcohol misuse in the ABCD cohort across more time points and the impact of personality traits such as impulsivity on these associations.

The promise and pitfalls of a strength-based approach to child poverty and neurocognitive development: Implications for policy

There has been significant progress in understanding the effects of childhood poverty on neurocognitive development. This progress has captured the attention of policymakers and promoted progressive policy reform. However, the prevailing emphasis on the harms associated with childhood poverty may have inadvertently perpetuated a deficit-based narrative, focused on the presumed shortcomings of children and families in poverty. This focus can have unintended consequences for policy (e.g., overlooking strengths) as well as public discourse (e.g., focusing on individual rather than systemic factors). Here, we join scientists across disciplines in arguing for a more well-rounded, "strength-based" approach, which incorporates the positive and/or adaptive developmental responses to experiences of social disadvantage. Specifically, we first show the value of this approach in understanding normative brain development across diverse human environments. We then highlight its application to educational and social policy, explore pitfalls and ethical considerations, and offer practical solutions to conducting strength-based research responsibly. Our paper re-ignites old and recent calls for a strength-based paradigm shift, with a focus on its application to developmental cognitive neuroscience. We also offer a unique perspective from a new generation of early-career researchers engaged in this work, several of whom themselves have grown up in conditions of poverty. Ultimately, we argue that a balanced strength-based scientific approach will be essential to building more effective policies.

A general exposome factor explains individual differences in functional brain network topography and cognition in youth

Childhood environments are critical in shaping cognitive neurodevelopment. With the increasing availability of large-scale neuroimaging datasets with deep phenotyping of childhood environments, we can now build upon prior studies that have considered relationships between one or a handful of environmental and neuroimaging features at a time. Here, we characterize the combined effects of hundreds of inter-connected and co-occurring features of a child's environment ("exposome") and investigate associations with each child's unique, multidimensional pattern of functional brain network organization ("functional topography") and cognition. We apply data-driven computational models to measure the exposome and define personalized functional brain networks in pre-registered analyses. Across matched discovery (n=5139, 48.5% female) and replication (n=5137, 47.1% female) samples from the Adolescent Brain Cognitive Development study, the exposome was associated with current (ages 9-10) and future (ages 11-12) cognition. Changes in the exposome were also associated with changes in cognition after accounting for baseline scores. Cross-validated ridge regressions revealed that the exposome is reflected in functional topography and can predict performance across cognitive domains. Importantly, a single measure capturing a child's exposome could more accurately and parsimoniously predict cognition than a wealth of personalized neuroimaging data, highlighting the importance of children's complex, multidimensional environments in cognitive neurodevelopment.

Cognitive stimulation as a mechanism linking socioeconomic status and neural function supporting working memory: a longitudinal fMRI study

Childhood experiences of low socioeconomic status are associated with alterations in neural function in the frontoparietal network and ventral visual stream, which may drive differences in working memory. However, the specific features of low socioeconomic status environments that contribute to these disparities remain poorly understood. Here, we examined experiences of cognitive deprivation (i.e. decreased variety and complexity of experience), as opposed to experiences of threat (i.e. violence exposure), as a potential mechanism through which family income contributes to alterations in neural activation during working memory. As part of a longitudinal study, 148 youth between aged 10 and 13 years completed a visuospatial working memory fMRI task. Early childhood low income, chronicity of low income in early childhood, and current income-to-needs were associated with task-related activation in the ventral visual stream and frontoparietal network. The association of family income with decreased activation in the lateral occipital cortex and intraparietal sulcus during working memory was mediated by experiences of cognitive deprivation. Surprisingly, however, family income and deprivation were not significantly related to working memory performance, and only deprivation was associated with academic achievement in this sample. Taken together, these findings suggest that early life low income and associated cognitive deprivation are important factors in neural function supporting working memory.

A research agenda for understanding how social inequality is linked to brain structure and function

Consistent evidence documents powerful effects of social inequality on health, well-being and academic achievement. Yet research on whether social inequality may also be linked to brain structure and function has, until recently, been rare. Here we describe three methodological approaches that can be used to study this question-single site, single study; multi-site, single study; and spatial meta-analysis. We review empirical work that, using these approaches, has observed associations between neural outcomes and structural measures of social inequality-including structural stigma, community-level prejudice, gender inequality, neighbourhood disadvantage and the generosity of the social safety net for low-income families. We evaluate the relative strengths and limitations of these approaches, discuss ethical considerations and outline directions for future research. In doing so, we advocate for a paradigm shift in cognitive neuroscience that explicitly incorporates upstream structural and contextual factors, which we argue holds promise for uncovering the neural correlates of social inequality.

Multilayer network associations between the exposome and childhood brain development

Growing up in a high poverty neighborhood is associated with elevated risk for academic challenges and health problems. Here, we take a data-driven approach to exploring how measures of children's environments relate to the development of their brain structure and function in a community sample of children between the ages of 4 and 10 years. We constructed exposomes including measures of family socioeconomic status, children's exposure to adversity, and geocoded measures of neighborhood socioeconomic status, crime, and environmental toxins. We connected the exposome to two structural measures (cortical thickness and surface area, n = 170) and two functional measures (participation coefficient and clustering coefficient, n = 130). We found dense connections within exposome and brain layers and sparse connections between exposome and brain layers. Lower family income was associated with thinner visual cortex, consistent with the theory that accelerated development is detectable in early-developing regions. Greater neighborhood incidence of high blood lead levels was associated with greater segregation of the default mode network, consistent with evidence that toxins are deposited into the brain along the midline. Our study demonstrates the utility of multilayer network analysis to bridge environmental and neural explanatory levels to better understand the complexity of child development.

Racial inequities and addiction research

What accounts for variation across racial and ethnic groups in drug use and harms related to substance use? While explanatory mechanisms for racial and ethnic disparities include differential access to and use of health services, a myriad of other factors, including racism and historical trauma, contribute to drug-related disparities. Furthermore, the addiction scientific workforce, like the full biomedical research enterprise, lacks diversity. This deficit undercuts U.S. scientific leadership and is a major challenge for the field. To address these entrenched problems, the National Institute on Drug Abuse (NIDA) is prioritizing research on health disparities and supporting multiple efforts to enhance scientific workforce diversity. Studies on substance use trends and emerging threats must measure disparities and track progress in reducing disparities, but also acknowledge the limitations of race and ethnicity-based data. Researchers must take the bold step of proposing studies that elucidate causal mechanisms which have the potential to be ameliorated by novel policies and practices. Critically, the impact of racism on all aspects of the substance use trajectory must be assessed to better tailor prevention, harm reduction, treatment, and recovery-support interventions to the specific circumstances of those who need them. Particular attention should be given to people who are incarcerated, who are experiencing homelessness, and who have a history of adverse childhood experiences. Training the next generation of the addiction science workforce needs to address structural barriers to participation with partnerships between funders, such as NIDA, and grantee organizations.

Effects of family income on brain functional connectivity in US children: associations with cognition

Higher family income (FI) is associated with larger cortical gray matter volume and improved cognitive performance in children. However, little is known about the effects of FI on brain functional and structural connectivity. This cross-sectional study investigates the effects of FI on brain connectivity and cognitive performance in 9- to 11-years old children (n = 8739) from the Adolescent Brain Cognitive Development (ABCD) study. Lower FI was associated with decreased global functional connectivity density (gFCD) in the default-mode network (DMN), inferior and superior parietal cortices and in posterior cerebellum, and increased gFCD in motor, auditory, and extrastriate visual areas, and in subcortical regions both for girls and boys. Findings demonstrated high reproducibility in Discovery and Reproducibility samples. Cognitive performance partially mediated the association between FI and DMN connectivity, whereas DMN connectivity did not mediate the association between FI and cognitive performance. In contrast, there was no significant association between FI and structural connectivity. Findings suggest that poor cognitive performance, which likely reflects multiple factors (genetic, nutritional, the level and quality of parental interactions, and educational exposure [1]), contributes to reduced DMN functional connectivity in children from low-income families. Follow-up studies are needed to help clarify if this leads to reductions in structural connectivity as these children age.

Brain capital, ecological development and sustainable environments

The importance of improving brain and mental health and developing sustainable environments is increasingly recognised. Understanding the syndemic interactions between these processes can help address contemporary societal challenges and foster global innovation. Here, we propose a green brain capital model that integrates environmental drivers of brain health and green skills necessary for long-term sustainability and discuss the role of interdisciplinary approaches in promoting individual and collective behavioural changes. We draw on existing literature and research to highlight the connections between brain health, environmental factors and green skills. Environmental factors and exposome can have long-lasting adverse effects on brain health, particularly in vulnerable populations. Investing in green brain capital can prepare societies to address global crises. Green skills, including creativity, ecological intelligence and digital literacy, are critical for promoting sustainable environments. Access to nature improves brain and mental health, and interdisciplinary fields such as neurourbanism can inform urban planning to benefit citizens' well-being. Building brain capital and environmental sustainability interactions requires increasing future generations' awareness, education and training. A comprehensive approach to green brain capital can enable greater societal scaling, synergistically protecting brain health and environmental sustainability.

Addressing the gaps between socioeconomic disparities and biological models of dementia

How do socioeconomic disparities shape brain health and disease? Ibáñez et al. discuss the need for further research into how wealth and socioeconomic status affect biological models of dementia, highlighting the biological ripple effects of socioeconomic inequalities and the importance of globally inclusive brain health research.