Effects of Antenatal Maternal Depressive Symptoms and Socio-Economic Status on Neonatal Brain Development are Modulated by Genetic Risk

Prenatal exposure to air pollution and maternal depression: Combined effects on brain aging and mental health in young adulthood

INTRODUCTION

Both maternal depression problems during pregnancy and prenatal exposure to air pollution have been associated with changes in the brain as well as worse mood and anxiety in the offspring in adulthood. However, it is not clear whether these effects are independent or whether and how they might interact and impact the brain age and mental health of the young adult offspring.

METHODS

A total of 202 mother-child dyads from a prenatal birth cohort were assessed for maternal depression during pregnancy through self-report questionnaires administered in the early 90s, exposure to air pollutants (Sulfur dioxide [SO2], nitrogen oxides [NOx], and suspended particle matter [SPM]) during each trimester based on maternal address and air quality data, mental health of the young adult offspring (28-30 years of age; 52% men, all of European ancestry) using self-report questionnaires for depression (Beck Depression Inventory), mood dysregulation (Profile of Mood States), anxiety (State-Trait Anxiety Inventory), and psychotic symptoms (Schizotypal Personality Questionnaire), and brain age, estimated from structural magnetic resonance imaging (MRI) and previously published neuroanatomical age prediction model using cortical thickness maps. The brain age gap estimate (BrainAGE) was computed by subtracting structural brain age from chronological age. Trajectories of exposure to air pollution during pregnancy were assessed using Growth Mixture Modeling. The interactions of prenatal depression and prenatal exposure to air pollutants on adult mental health and BrainAGE were assessed using hierarchical linear regression.

RESULTS

We revealed two distinct trajectories of exposure to air pollution during pregnancy: "early exposure," characterized by high exposure during the first trimester, followed by a steady decrease, and "late exposure," characterized by low exposure during the first trimester, followed by a steady increase in the exposure during the subsequent trimesters. Maternal depression during the first half of pregnancy interacted with NOX exposure trajectory, predicting mood dysregulation and schizotypal symptoms in young adults. In addition, maternal depression during the second half of pregnancy interacted with both NOx and SO2 exposure trajectories, respectively, and predicted BrainAGE in young adults. In those with early exposure to NOx, maternal depression during pregnancy was associated with worse mental health and accelerated brain aging in young adulthood. In contrast, in those with early exposure to SO2, maternal depression during pregnancy was associated with slower brain aging in young adulthood.

CONCLUSIONS

Our findings provide the first evidence of the combined effects of prenatal exposure to air pollution and maternal depression on mental health outcomes and brain age in young adult offspring. Moreover, they point out the importance of the timing and trajectory of the exposure during prenatal development.

Early life adversities, psychopathologies and novel pharmacological strategies

Exposure to adversities during early life stages (early life adversities - ELA), ranging from pregnancy to adolescence, represents a major risk factor for the vulnerability to mental disorders. Hence, it is important to understand the molecular and functional underpinning of such relationship, in order to develop strategies aimed at reducing the psychopathologic burden associated with ELA, which may eventually lead to a significant improvement in clinical practice. In this review, we will initially recapitulate clinical and preclinical evidence supporting the link between ELA and psychopathology and we will primarily discuss the main biological mechanisms that have been described as potential mediators of the effects of ELA on the psychopathologic risk, including the role for genetic factors as well as sex differences. The knowledge emerging from these studies may be instrumental for the development of novel therapeutic strategies aimed not only at correcting the deficits that emerge from ELA exposure, but also in preventing the manifestation of a full-blown psychopathologic condition. With this respect, we will specifically focus on adolescence as a key time frame for disease onset as well as for early therapeutic intervention. We believe that incorporating clinical and preclinical research data in the context of early life adversities can be instrumental to elucidate the mechanisms contributing to the risk for psychopathology or that may promote resilience. This will ultimately allow the identification of 'at risk' individuals who may benefit from specific forms of interventions that, by interfering with disease trajectories, could result in more benign clinical outcomes.

Prenatal Social Determinants of Health: Narrative review of maternal environments and neonatal brain development

The Social Determinants of Health, a set of social factors including socioeconomic status, community context, and neighborhood safety among others, are well-known predictors of mental and physical health across the lifespan. Recent research has begun to establish the importance of these social factors at the earliest points of brain development, including during the prenatal period. Prenatal socioeconomic status, perceived stress, and neighborhood safety have all been reported to impact neonatal brain structure and function, with exploratory work suggesting subsequent effects on infant and child behavior. Secondary effects of the Social Determinants of Health, such as maternal sleep and psychopathology during pregnancy, have also been established as important predictors of infant brain development. This research not only establishes prenatal Social Determinants of Health as important predictors of future outcomes but may be effectively applied even before birth. Future research replicating and extending the effects in this nascent literature has great potential to produce more specific and mechanistic understanding of the social factors that shape early neurobehavioral development. IMPACT: This review synthesizes the research to date examining the effects of the Social Determinants of Health during the prenatal period and neonatal brain outcomes. Structural, functional, and diffusion-based imaging methodologies are included along with the limited literature assessing subsequent infant behavior. The degree to which results converge between studies is discussed, in combination with the methodological and sampling considerations that may contribute to divergence in study results. Several future directions are identified, including new theoretical approaches to assessing the impact of the Social Determinants of Health during the perinatal period.

Advances in fetal and neonatal neuroimaging and everyday exposures

The complex, tightly regulated process of prenatal brain development may be adversely affected by "everyday exposures" such as stress and environmental pollutants. Researchers are only just beginning to understand the neural sequelae of such exposures, with advances in fetal and neonatal neuroimaging elucidating structural, microstructural, and functional correlates in the developing brain. This narrative review discusses the wide-ranging literature investigating the influence of parental stress on fetal and neonatal brain development as well as emerging literature assessing the impact of exposure to environmental toxicants such as lead and air pollution. These 'everyday exposures' can co-occur with other stressors such as social and financial deprivation, and therefore we include a brief discussion of neuroimaging studies assessing the effect of social disadvantage. Increased exposure to prenatal stressors is associated with alterations in the brain structure, microstructure and function, with some evidence these associations are moderated by factors such as infant sex. However, most studies examine only single exposures and the literature on the relationship between in utero exposure to pollutants and fetal or neonatal brain development is sparse. Large cohort studies are required that include evaluation of multiple co-occurring exposures in order to fully characterize their impact on early brain development. IMPACT: Increased prenatal exposure to parental stress and is associated with altered functional, macro and microstructural fetal and neonatal brain development. Exposure to air pollution and lead may also alter brain development in the fetal and neonatal period. Further research is needed to investigate the effect of multiple co-occurring exposures, including stress, environmental toxicants, and socioeconomic deprivation on early brain development.

Independent Prediction of Child Psychiatric Symptoms by Maternal Mental Health and Child Polygenic Risk Scores

OBJECTIVE

Prenatal maternal symptoms of depression and anxiety are associated with an increased risk for child socioemotional and behavioral difficulties, supporting the fetal origins of mental health hypothesis. However, to date, studies have not considered specific genomic risk as a possible confound.

METHOD

The Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (n = 5,546) was used to test if child polygenic risk score for attention-deficit/hyperactivity disorder (ADHD), schizophrenia, or depression confounds or modifies the impact of prenatal maternal depression and anxiety on child internalizing, externalizing, and total emotional/behavioral symptoms from age 4 to 16 years. Longitudinal child and adolescent symptom data were analyzed in the ALSPAC cohort using generalized estimating equations. Replication analyses were done in an independent cohort (Prevention of Preeclampsia and Intrauterine Growth Restriction [PREDO] cohort; n = 514) from Finland, which provided complementary measures of maternal mental health and child psychiatric symptoms.

RESULTS

Maternal depression and anxiety and child polygenic risk scores independently and additively predicted behavioral and emotional symptoms from childhood through mid-adolescence. There was a robust prediction of child and adolescent symptoms from both prenatal maternal depression (generalized estimating equation estimate = 0.093, 95% CI 0.065-0.121, p = 2.66 × 10-10) and anxiety (generalized estimating equation estimate = 0.065, 95% CI 0.037-0.093, p = 1.62 × 10-5) after adjusting for child genomic risk for mental disorders. There was a similar independent effect of maternal depression (B = 0.156, 95% CI 0.066-0.246, p = .001) on child symptoms in the PREDO cohort. Genetically informed sensitivity analyses suggest that shared genetic risk only partially explains the reported association between prenatal maternal depression and offspring mental health.

CONCLUSION

These findings highlight the genomic contribution to the fetal origins of mental health hypothesis and further evidence that prenatal maternal depression and anxiety are robust in utero risks for child and adolescent psychiatric symptoms.

PLAIN LANGUAGE SUMMARY

Depression and anxiety affect approximately 15% of pregnant women, and children exposed to maternal depression or anxiety during pregnancy are at higher risk of developing mental health problems. However, the degree to which shared genetics explains the association between maternal and child mental health is unknown. In this study the authors generated polygenic risk scores (PRS), which provide a single measure of genetic risk for complex traits, to investigate the impact of shared genetic risk on the development of childhood mental health problems. Utilizing two longitudinal studies (n = 6,060), the authors found that PRS only partially explained the association between prenatal maternal depression and childhood mental health problems. These analyses show prenatal maternal depression remained a significant predictor of childhood mental health problems after accounting for shared genetic risk, further highlighting that prenatal maternal mental health is a robust predictor of child and adolescent mental health problems.

The effect of prenatal maternal distress on offspring brain development: A systematic review

BACKGROUND

Prenatal maternal distress can negatively affect pregnancy outcomes, yet its impact on the offspring's brain structure and function remains unclear. This systematic review summarizes the available literature on the relationship between prenatal maternal distress and brain development in fetuses and infants up to 12 months of age.

METHODS

We searched Central, Embase, MEDLINE, PsycINFO, and PSYNDEXplus for studies published between database inception and December 2023. Studies were included if prenatal maternal anxiety, stress, and/or depression was assessed, neuroimaging was used to examine the offspring, and the offspring's brain was imaged within the first year of life. The quality of the included studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-II.

RESULTS

Out of the 1516 studies retrieved, 71 met our inclusion criteria. Although the studies varied greatly in their methodology, the results generally pointed to structural and functional aberrations in the limbic system, prefrontal cortex, and insula in fetuses and infants prenatally exposed to maternal distress.

CONCLUSIONS

The hippocampus, amygdala, and prefrontal cortex have a high density of glucocorticoid receptors, which play a key role in adapting to stressors and maintaining stress-related homeostasis. We thus conclude that in utero exposure to maternal distress prompts these brain regions to adapt by undergoing structural and functional changes, with the consequence that these alterations increase the risk for developing a neuropsychiatric illness later on. Future research should investigate the effect of providing psychological support for pregnant women on the offspring's early brain development.

Maternal prenatal lead levels and neonatal brain volumes: Testing moderations by maternal depressive symptoms and family income

There is considerable evidence that prenatal lead exposure is detrimental to child cognitive and socio-emotional development. Further evidence suggests that the effects of prenatal lead on developmental outcomes may be conditional upon exposure to social stressors, such as maternal depression and low socioeconomic status. However, no studies have examined associations between these co-occurring stressors during pregnancy and neonatal brain volumes. Leveraging a sample of 101 mother-infant dyads followed beginning in mid-pregnancy, we examined the main effects of prenatal urinary lead levels on neonatal lateralized brain volumes (left and right hippocampus, amygdala, cerebellum, frontal lobes) and total gray matter. We additionally tested for moderations between lead and depressive symptoms and between lead and family income relative to the federal poverty level (FPL) on the same neurodevelopmental outcomes. Analyses of main effects indicated that prenatal lead was significantly (ps < 0.05) associated with reduced right and left amygdala volumes (βs = -0.23- -0.20). The testing and probing of cross-product interaction terms using simple slopes indicated that the negative effect of lead on the left amygdala was conditional upon mothers having low depressive symptoms or high income relative to the FPL. We interpret the results in the context of trajectories of prenatal and postnatal brain development and susceptibility to low levels of prenatal lead in the context of other social stressors.

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

Socioeconomic status (SES) is associated with children's brain and behavioral development. Several theories propose that early experiences of adversity or low SES can alter the pace of neurodevelopment during childhood and adolescence. These theories make contrasting predictions about whether adverse experiences and low SES are associated with accelerated or delayed neurodevelopment. We contextualize these predictions within the context of normative development of cortical and subcortical structure and review existing evidence on SES and structural brain development to adjudicate between competing hypotheses. Although none of these theories are fully consistent with observed SES-related differences in brain development, existing evidence suggests that low SES is associated with brain structure trajectories more consistent with a delayed or simply different developmental pattern than an acceleration in neurodevelopment.

Genetic Influences on the Developing Young Brain and Risk for Neuropsychiatric Disorders

Imaging genetics provides an opportunity to discern associations between genetic variants and brain imaging phenotypes. Historically, the field has focused on adults and adolescents; very few imaging genetics studies have focused on brain development in infancy and early childhood (from birth to age 6 years). This is an important knowledge gap because developmental changes in the brain during the prenatal and early postnatal period are regulated by dynamic gene expression patterns that likely play an important role in establishing an individual's risk for later psychiatric illness and neurodevelopmental disabilities. In this review, we summarize findings from imaging genetics studies spanning from early infancy to early childhood, with a focus on studies examining genetic risk for neuropsychiatric disorders. We also introduce the Organization for Imaging Genomics in Infancy (ORIGINs), a working group of the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) consortium, which was established to facilitate large-scale imaging genetics studies in infancy and early childhood.

Prenatal programming of environmental sensitivity

According to several theories, people differ in their sensitivity to environmental influences with some more susceptible than others to both supportive and adverse contextual conditions. Such differences in environmental sensitivity have a genetic basis but are also shaped by environmental factors. Herein we narratively build on our previous work proposing that prenatal experiences contribute to the development of environmental sensitivity. This hypothesis of prenatal programming of postnatal plasticity has considerable empirical support. After presenting illustrative animal and human evidence consistent with this claim, we discuss a range of biological mechanisms likely involved in the pathway from prenatal stress exposure to postnatal environmental sensitivity. We also consider work suggesting that genetic differences, gender, as well as the timing, duration and intensity of prenatal exposures may moderate the effects of prenatal programming on postnatal environmental susceptibility or sensitivity. Before concluding, we highlight "unknowns in the prenatal programming of environmental sensitivity" and their practical implications. Ultimately, we conclude that prenatal stress does not necessarily predispose individuals to problematical development, but rather increases sensitivity to both adverse and supportive postnatal contexts. Thus, prenatal stress may actually foster positive development if paired with supportive and caring postnatal environments.

Prenatal depressive symptoms and childhood development of brain limbic and default mode network structure

Prenatal depressive symptoms are linked to negative child behavioral and cognitive outcomes and predict later psychopathology in adolescent children. Prior work links prenatal depressive symptoms to child brain structure in regions like the amygdala; however, the relationship between symptoms and the development of brain structure over time remains unclear. We measured maternal depressive symptoms during pregnancy and acquired longitudinal T1-weighted and diffusion imaging data in children (n = 111; 60 females) between 2.6 and 8 years of age. Controlling for postnatal symptoms, we used linear mixed effects models to test relationships between prenatal depressive symptoms and age-related changes in (i) amygdala and hippocampal volume and (ii) structural properties of the limbic and default-mode networks using graph theory. Higher prenatal depressive symptoms in the second trimester were associated with more curvilinear trajectories of left amygdala volume changes. Higher prenatal depressive symptoms in the third trimester were associated with slower age-related changes in limbic global efficiency and average node degree across childhood. Our work provides evidence that moderate symptoms of prenatal depression in a low sociodemographic risk sample are associated with structural brain development in regions and networks implicated in emotion processing.

Association of Maternal Depression During Pregnancy and Recent Stress With Brain Age Among Adult Offspring

IMPORTANCE

Maternal mental health problems during pregnancy are associated with altered neurodevelopment in offspring, but the long-term relationship between these prenatal risk factors and offspring brain structure in adulthood remains incompletely understood due to a paucity of longitudinal studies.

OBJECTIVE

To evaluate the association between exposure to maternal depression in utero and offspring brain age in the third decade of life, and to evaluate recent stressful life events as potential moderators of this association.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined the 30-year follow-up of a Czech prenatal birth cohort with a within-participant design neuroimaging component in young adulthood conducted from 1991 to 2022. Participants from the European Longitudinal Study of Pregnancy and Childhood prenatal birth cohort were recruited for 2 magnetic resonance imaging (MRI) follow-ups, one between ages 23 and 24 years (early 20s) and another between ages 28 and 30 years (late 20s).

EXPOSURES

Maternal depression during pregnancy; stressful life events in the past year experienced by the young adult offspring.

MAIN OUTCOMES AND MEASURES

Gap between estimated neuroanatomical vs chronological age at MRI scan (brain age gap estimation [BrainAGE]) calculated once in participants' early 20s and once in their late 20s, and pace of aging calculated as the differences between BrainAGE at the 2 MRI sessions in young adulthood.

RESULTS

A total of 260 individuals participated in the second neuroimaging follow-up (mean [SD] age, 29.5 [0.6] years; 135 [52%] male); MRI data for both time points and a history of maternal depression were available for 110 participants (mean [SD] age, 29.3 [0.6] years; 56 [51%] male). BrainAGE in participants' early 20s was correlated with BrainAGE in their late 20s (r = 0.7, P < .001), and a previously observed association between maternal depression during pregnancy and BrainAGE in their early 20s persisted in their late 20s (adjusted R2 = 0.04; P = .04). However, no association emerged between maternal depression during pregnancy and the pace of aging between the 2 MRI sessions. The stability of the associations between maternal depression during pregnancy and BrainAGE was also supported by the lack of interactions with recent stress. In contrast, more recent stress was associated with greater pace of aging between the 2 MRI sessions, independent of maternal depression (adjusted R2 = 0.09; P = .01).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that maternal depression and recent stress may have independent associations with brain age and the pace of aging, respectively, in young adulthood. Prevention and treatment of depression in pregnant mothers may have long-term implications for offspring brain development.

Subcortical brain volumes in young infants exposed to antenatal maternal depression: Findings from a South African birth cohort

BACKGROUND

Several studies have reported enlarged amygdala and smaller hippocampus volumes in children and adolescents exposed to maternal depression. It is unclear whether similar volumetric differences are detectable in the infants' first weeks of life, following exposure in utero. We investigated subcortical volumes in 2-to-6 week old infants exposed to antenatal maternal depression (AMD) from a South African birth cohort.

METHODS

AMD was measured with the Beck Depression Inventory 2nd edition (BDI-II) at 28-32 weeks gestation. T2-weighted structural images were acquired during natural sleep on a 3T Siemens Allegra scanner. Subcortical regions were segmented based on the University of North Carolina neonatal brain atlas. Volumetric estimates were compared between AMD-exposed (BDI-II ⩾ 20) and unexposed (BDI-II < 14) infants, adjusted for age, sex and total intracranial volume using analysis of covariance.

RESULTS

Larger volumes were observed in AMD-exposed (N = 49) compared to unexposed infants (N = 75) for the right amygdala (1.93% difference, p = 0.039) and bilateral caudate nucleus (left: 5.79% difference, p = 0.001; right: 6.09% difference, p < 0.001). A significant AMD-by-sex interaction was found for the hippocampus (left: F(1,118) = 4.80, p = 0.030; right: F(1,118) = 5.16, p = 0.025), reflecting greater volume in AMD-exposed females (left: 5.09% difference, p = 0.001, right: 3.54% difference, p = 0.010), but not males.

CONCLUSIONS

Volumetric differences in subcortical regions can be detected in AMD-exposed infants soon after birth, suggesting structural changes may occur in utero. Female infants might exhibit volumetric changes that are not observed in male infants. The potential mechanisms underlying these early volumetric differences, and their significance for long-term child mental health, require further investigation.

Maternal depressive symptoms, neonatal white matter, and toddler social-emotional development

Maternal prenatal depression is associated with increased likelihood of neurodevelopmental and psychiatric conditions in offspring. The relationship between maternal depression and offspring outcome may be mediated by in-utero changes in brain development. Recent advances in magnetic resonance imaging (MRI) have enabled in vivo investigations of neonatal brains, minimising the effect of postnatal influences. The aim of this study was to examine associations between maternal prenatal depressive symptoms, infant white matter, and toddler behaviour. 413 mother-infant dyads enrolled in the developing Human Connectome Project. Mothers completed the Edinburgh Postnatal Depression Scale (median = 5, range = 0-28, n = 52 scores ≥ 11). Infants (n = 223 male) (median gestational age at birth = 40 weeks, range 32.14-42.29) underwent MRI (median postmenstrual age at scan = 41.29 weeks, range 36.57-44.71). Fixel-based fibre metrics (mean fibre density, fibre cross-section, and fibre density modulated by cross-section) were calculated from diffusion imaging data in the left and right uncinate fasciculi and cingulum bundle. For n = 311, internalising and externalising behaviour, and social-emotional abilities were reported at a median corrected age of 18 months (range 17-24). Statistical analysis used multiple linear regression and mediation analysis with bootstrapping. Maternal depressive symptoms were positively associated with infant fibre density in the left (B = 0.0005, p = 0.003, q = 0.027) and right (B = 0.0006, p = 0.003, q = 0.027) uncinate fasciculus, with left uncinate fasciculus fibre density, in turn, positively associated with social-emotional abilities in toddlerhood (B = 105.70, p = 0.0007, q = 0.004). In a mediation analysis, higher maternal depressive symptoms predicted toddler social-emotional difficulties (B = 0.342, t(307) = 3.003, p = 0.003), but this relationship was not mediated by fibre density in the left uncinate fasciculus (Sobel test p = 0.143, bootstrapped indirect effect = 0.035, SE = 0.02, 95% CI: [-0.01, 0.08]). There was no evidence of an association between maternal depressive and cingulum fibre properties. These findings suggest that maternal perinatal depressive symptoms are associated with neonatal uncinate fasciculi microstructure, but not fibre bundle size, and toddler behaviour.

Identification of eQTLs and differential gene expression associated with fetal programming in beef cattle

This study assessed differential gene expression and identified expression quantitative trait loci (eQTLs) from samples of Longissimus lumborum muscle from bulls at 15 months of age submitted to different prenatal nutrition. Upon confirmation of pregnancy, 126 dams were separated into three diet treatments varying the period of inclusion of energy protein supplementation (NP, PP, and FP). At calving, 63 males were genotyped with GGP LD BeadChip. The skeletal muscle of 15 bulls was sequenced (RNA-seq) at 15 months of age. The EdgeR package was used for differential gene expression and principal component analysis (PCA), and the Matrix eQTL package was used for the eQTLs analysis (R statistical). The functional enrichment analysis was performed using the MetaCore® software. No genes differentially expressed were found between treatments (FDR > 0.05); nevertheless, we found 179 cis-tag-eQTLs and 20,762 trans-tag-eQTLs (FDR < 0.05) after linkage disequilibrium analysis. The functional enrichment analysis identified terms from gene ontology related to genes associated to trans-eQTLs (FDR < 0.05) as well as metabolic pathways (> gScore). Most biological pathways and genes found had been previously associated to fetal programming. The different prenatal supplementation strategies did not impact on muscle transcriptome of bulls. Additionally, there is a link between genotype and gene expression levels related to developmental traits in Nellore cattle.

Prenatal stress and its association with amygdala-related structural covariance patterns in youth

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Prenatal exposure to stress predicts amygdala degree centrality in young adulthood.

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High (vs. low) stress group showed lower structural covariance degree of amygdala.

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These effects were particularly significant in men.

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Global network parameters did not drive these effects.

Background

Prenatal stress influences brain development and mood disorder vulnerability. Brain structural covariance network (SCN) properties based on inter-regional volumetric correlations may reflect developmentally-mediated shared plasticity among regions. Childhood trauma is associated with amygdala-centric SCN reorganization patterns, however, the impact of prenatal stress on SCN properties remains unknown.

Methods

The study included participants from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) with archival prenatal stress data and structural MRI acquired in young adulthood (age 23–24). SCNs were constructed based on Freesurfer-extracted volumes of 7 subcortical and 34 cortical regions. We compared amygdala degree centrality, a measure of hubness, between those exposed to high vs. low (median split) prenatal stress, defined by maternal reports of stressful life events during the first (n = 93, 57% female) and second (n = 125, 54% female) half of pregnancy. Group differences were tested across network density thresholds (5–40%) using 10,000 permutations, with sex and intracranial volume as covariates, followed by sex-specific analyses. Finally, we sought to replicate our results in an independent all-male sample (n = 450, age 18–20) from the Avon Longitudinal Study of Parents and Children (ALSPAC).

Results

The high-stress during the first half of pregnancy ELSPAC group showed lower amygdala degree particularly in men, who demonstrated this difference at 10 consecutive thresholds, with no significant differences in global network properties. At the lowest significant density threshold, amygdala volume was positively correlated with hippocampus, putamen, rostral anterior and posterior cingulate, transverse temporal, and pericalcarine cortex in the low-stress (p(FDR) < 0.027), but not the high-stress (p(FDR) > 0.882) group. Although amygdala degree was nominally lower across thresholds in the high-stress ALSPAC group, these results were not significant.

Conclusion

Unlike childhood trauma, prenatal stress may shift SCN towards a less amygdala-centric SCN pattern, particularly in men. These findings did not replicate in an all-male ALSPAC sample, possibly due to the sample’s younger age and lower prenatal stress exposure.

Negative emotionality as a candidate mediating mechanism linking prenatal maternal mood problems and offspring internalizing behaviour

Negative emotionality (NE) was evaluated as a candidate mechanism linking prenatal maternal affective symptoms and offspring internalizing problems during the preschool/early school age period. The participants were 335 mother-infant dyads from the Maternal Adversity, Vulnerability and Neurodevelopment project. A Confirmatory Bifactor Analysis (CFA) based on self-report measures of prenatal depression and pregnancy-specific anxiety generated a general factor representing overlapping symptoms of prenatal maternal psychopathology and four distinct symptom factors representing pregnancy-specific anxiety, negative affect, anhedonia and somatization. NE was rated by the mother at 18 and 36 months. CFA based on measures of father, mother, child-rated measures and a semistructured interview generated a general internalizing factor representing overlapping symptoms of child internalizing psychopathology accounting for the unique contribution of each informant. Path analyses revealed significant relationships among the general maternal affective psychopathology, the pregnancy- specific anxiety, and the child internalizing factors. Child NE mediated only the relationship between pregnancy-specific anxiety and the child internalizing factors. We highlighted the conditions in which prenatal maternal affective symptoms predicts child internalizing problems emerging early in development, including consideration of different mechanistic pathways for different maternal prenatal symptom presentations and child temperament.

Maternal childhood maltreatment and perinatal outcomes: A systematic review

BACKGROUND

Maternal childhood maltreatment (MCM) is linked to poor perinatal outcomes but the evidence base lacks cohesion. We explore the impact of MCM on four perinatal outcome domains: pregnancy and obstetric; maternal mental health; infant; and the quality of the care-giving environment. Mechanisms identified in the included studies are discussed in relation to the maternal programming hypothesis and directions for future research.

METHOD

We completed a comprehensive literature search of eight electronic databases. Independent quality assessments were conducted and PRISMA protocols applied to data extraction.

RESULTS

Inclusion criteria was met by N = 49 studies. MCM was consistently associated with difficulties in maternal and infant emotional regulation and with disturbances in the mother-infant relationship. Directly observed and maternal-reported difficulties in the mother-infant relationship were often mediated by mothers' current symptoms of psychopathology. Direct and mediated associations between MCM and adverse pregnancy and obstetric outcomes were suggested by a limited number of studies. Emotional and sexual abuse were the most consistent MCM subtype significantly associated with adverse perinatal outcomes.

LIMITATIONS

A meta-analysis was not possible due to inconsistent reporting and the generally small number of studies for most perinatal outcomes.

CONCLUSIONS

MCM is associated with adverse perinatal outcomes for mothers' and infants. Evidence suggests these associations are mediated by disruptions to maternal emotional functioning. Future research should explore biological and psychosocial mechanisms underpinning observed associations between specific subtypes of MCM and adverse perinatal outcomes. Services have a unique opportunity to screen for MCM and detect women and infants at risk of adverse outcomes during the perinatal period.

Fetal programming of human energy homeostasis brain networks: Issues and considerations

In this paper, we present a transdisciplinary framework and testable hypotheses regarding the process of fetal programming of energy homeostasis brain circuitry. Our model proposes that key aspects of energy homeostasis brain circuitry already are functional by the time of birth (with substantial interindividual variation); that this phenotypic variation at birth is an important determinant of subsequent susceptibility for energy imbalance and childhood obesity risk; and that this brain circuitry exhibits developmental plasticity, in that it is influenced by conditions during intrauterine life, particularly maternal-placental-fetal endocrine, immune/inflammatory, and metabolic processes and their upstream determinants. We review evidence that supports the scientific premise for each element of this formulation, identify future research directions, particularly recent advances that may facilitate a better quantification of the ontogeny of energy homeostasis brain networks, highlight animal and in vitro-based approaches that may better address the determinants of interindividual variation in energy homeostasis brain networks, and discuss the implications of this formulation for the development of strategies targeted towards the primary prevention of childhood obesity.

Cortical Development Mediates Association of Prenatal Maternal Depressive Symptoms and Child Reward Sensitivity: A Longitudinal Study

OBJECTIVE

Maternal depression during pregnancy has long-term impacts on offspring. This study used neuroimaging and behavioral data from children aged 4 to 6 years and investigated whether prenatal maternal depressive symptoms (pre-MDS) associated with child cortical morphological development and subsequent reward-related behaviors in preschoolers.

METHOD

Pre-MDS was measured using the Edinburgh Postnatal Depression Scale at 26 weeks of pregnancy. Children (n = 130) underwent structural magnetic resonance imaging (MRI) at both 4 and 6 years of age. Child sensitivity to reward and punishment was reported by mothers when children were 6 years of age. Linear mixed-effect models examined pre-MDS associations with child cortical thickness and surface area. Mediation analysis examined whether cortical development mediated associations between pre-MDS and child sensitivity to reward and punishment.

RESULTS

The 3-way interactions of pre-MDS, age, and sex on cortical thickness and surface area were not statistically significant. We found a significant interaction of pre-MDS with sex on the cortical surface area but not on thickness or their growth from 4 to 6 years, adjusting for ethnicity, socioeconomic status, baseline age, and postnatal MDS as covariates. Higher pre-MDS scores were associated with larger surface areas in the prefrontal cortex, superior temporal gyrus, and superior parietal lobe (SPL) in boys, whereas the opposite pattern was seen in girls. The SPL surface area mediated the relationship between pre-MDS and sensitivity to reward in girls.

CONCLUSION

Prenatal maternal depression alters the cortical morphology of pre-schoolers in a sex-dependent manner.

Maternal Prenatal Anxiety and the Fetal Origins of Epigenetic Aging

BACKGROUND

The fetal origins of mental health is a well-established framework that currently lacks a robust index of the biological embedding of prenatal adversity. The Pediatric-Buccal-Epigenetic (PedBE) clock is a novel epigenetic tool that associates with aspects of the prenatal environment, but additional validation in longitudinal datasets is required. Likewise, the relationship between prenatal maternal mental health and the PedBE clock has not been described.

METHODS

Longitudinal cohorts from the Netherlands (Basal Influences on Baby Development [BIBO] n = 165) and Singapore (Growing Up in Singapore Towards Healthy Outcomes [GUSTO] n = 340) provided data on prenatal maternal anxiety and longitudinal assessments of buccal cell-derived genome-wide DNA methylation assessed at 6 and 10 years of age in BIBO, and at 3, 9, and 48 months of age in GUSTO. Measures of epigenetic age acceleration were calculated using the PedBE clock and benchmarked against an established multi-tissue epigenetic predictor.

RESULTS

Prenatal maternal anxiety predicted child PedBE epigenetic age acceleration in both cohorts, with effects largely restricted to males and not females. These results were independent of obstetric, socioeconomic, and genetic risk factors, with a larger effect size for prenatal anxiety than depression. PedBE age acceleration predicted increased externalizing symptoms in males from mid- to late childhood in the BIBO cohort only.

CONCLUSIONS

These findings point to the fetal origins of epigenetic age acceleration and reveal an increased sensitivity in males. Convergent evidence underscores the societal importance of providing timely and effective mental health support to pregnant individuals, which may have lasting consequences for both mother and child.

Prenatal depression exposure alters white matter integrity and neurodevelopment in early childhood

Prenatal exposure to maternal depression increases the risk for onset of emotional and behavioral disorders in children. We investigated the effects of exposure to prenatal depression on white matter microstructural integrity at birth and at 2-3 years, and associated neurodevelopment. Diffusion-weighted images were acquired for children of the Drakenstein Child Health Study at 2-4 weeks postpartum (n=70, 47% boys) and at 2-3 years of age (n=60, 58% boys). Tract-Based Spatial Statistics was used to compare, using an ROI based approach, diffusion tensor metrics across groups defined by presence (>19 on Beck's Depression Inventory and/or >12 on the Edinburgh Postnatal Depression Scale) or absence (below depression thresholds) of depression, and associations with neurodevelopmental measures at age 2-3 years were determined. We did not detect group differences in white matter integrity at neonatal age, but at 2-3 years, children in the exposed group demonstrated higher fractional anisotropy, and lower mean and radial diffusivity in association tracts compared to controls. This was notable in the sagittal stratum (radial diffusivity: p<0.01). Altered white matter integrity metrics were also observed in projection tracts, including the corona radiata, which associated with cognitive and motor outcomes in exposed 2-3-year-olds (p<0.05). Our findings of widespread white matter alterations in 2-3-year-old children with prenatal exposure to depression are consistent with previous findings, as well as with neuroimaging findings in adults with major depression. Further, we identified novel associations of altered white matter integrity with cognitive development in depression-exposed children, suggesting that these neuroimaging findings may have early functional impact.

Sex-specific associations between maternal pregnancy-specific anxiety and newborn amygdalar volumes - preliminary findings from the FinnBrain Birth Cohort Study

Previous literature links maternal pregnancy-specific anxiety (PSA) with later difficulties in child emotional and social cognition as well as memory, functions closely related to the amygdala and the hippocampus. Some evidence also suggests that PSA affects child amygdalar volumes in a sex-dependent way. However, no studies investigating the associations between PSA and newborn amygdalar and hippocampal volumes have been reported. We investigated the associations between PSA and newborn amygdalar and hippocampal volumes and whether associations are sex-specific in 122 healthy newborns (68 males/54 females) scanned at 2-5 weeks postpartum. PSA was measured at gestational week 24 with the Pregnancy-Related Anxiety Questionnaire Revised 2 (PRAQ-R2). The associations were analyzed with linear regression controlling for confounding variables. PSA was associated positively with left amygdalar volume in girls, but no significant main effect was found in the whole group or in boys. No significant main or sex-specific effect was found for hippocampal volumes. Although this was an exploratory study, the findings suggest a sexually dimorphic association of mid-pregnancy PSA with newborn amygdalar volumes.

Genetically-predicted prefrontal DRD4 gene expression modulates differentiated brain responses to food cues in adolescent girls and boys

The dopamine receptor 4 (DRD4) in the prefrontal cortex (PFC) acts to modulate behaviours including cognitive control and motivation, and has been implicated in behavioral inhibition and responsivity to food cues. Adolescence is a sensitive period for the development of habitual eating behaviors and obesity risk, with potential mediation by development of the PFC. We previously found that genetic variations influencing DRD4 function or expression were associated with measures of laboratory and real-world eating behavior in girls and boys. Here we investigated brain responses to high energy–density (ED) and low-ED food cues using an fMRI task conducted in the satiated state. We used the gene-based association method PrediXcan to estimate tissue-specific DRD4 gene expression in prefrontal brain areas from individual genotypes. Among girls, those with lower vs. higher predicted prefrontal DRD4 expression showed lesser activation to high-ED and low-ED vs. non-food cues in a distributed network of regions implicated in attention and sensorimotor processing including middle frontal gyrus, and lesser activation to low-ED vs non-food cues in key regions implicated in valuation including orbitofrontal cortex and ventromedial PFC. In contrast, males with lower vs. higher predicted prefrontal DRD4 expression showed minimal differences in food cue response, namely relatively greater activation to high-ED and low-ED vs. non-food cues in the inferior parietal lobule. Our data suggest sex-specific effects of prefrontal DRD4 on brain food responsiveness in adolescence, with modulation of distributed regions relevant to cognitive control and motivation observable in female adolescents.

How prenatal exposures shape the infant brain: Insights from infant neuroimaging studies

Brain development during the prenatal period is rapid and unparalleled by any other time during development. Biological systems undergoing rapid development are at higher risk for disorganizing influences. Therefore, certain prenatal exposures impact brain development, increasing risk for negative neurodevelopmental outcome. While prenatal exposures have been associated with cognitive and behavioral outcomes later in life, the underlying macroscopic brain pathways remain unclear. Here, we review magnetic resonance imaging (MRI) studies investigating the association between prenatal exposures and infant brain development focusing on prenatal exposures via maternal physical health factors, maternal mental health factors, and maternal drug and medication use. Further, we discuss the need for studies to consider multiple prenatal exposures in parallel and suggest future directions for this body of research.

Exposure to prenatal maternal distress and infant white matter neurodevelopment

The prenatal period represents a critical time for brain growth and development. These rapid neurological advances render the fetus susceptible to various influences with life-long implications for mental health. Maternal distress signals are a dominant early life influence, contributing to birth outcomes and risk for offspring psychopathology. This prospective longitudinal study evaluated the association between prenatal maternal distress and infant white matter microstructure. Participants included a racially and socioeconomically diverse sample of 85 mother-infant dyads. Prenatal distress was assessed at 17 and 29 weeks' gestational age (GA). Infant structural data were collected via diffusion tensor imaging at 42-45 weeks' postconceptional age. Findings demonstrated that higher prenatal maternal distress at 29 weeks' GA was associated with increased fractional anisotropy (b = .283, t(64) = 2.319, p = .024) and with increased axial diffusivity (b = .254, t(64) = 2.067, p = .043) within the right anterior cingulate white matter tract. No other significant associations were found with prenatal distress exposure and tract fractional anisotropy or axial diffusivity at 29 weeks' GA, nor earlier in gestation.

Effect of parental depressive symptoms on offspring's brain structure and function: A systematic review of neuroimaging studies

Perinatal Depression (PND) is a severe mental disorder that appears during pregnancy or in the post-partum. Although PND has been associated with behavioral problems in the offspring, its effects on brain development are unclear. With this review we aimed at summarizing the existing literature on the effects of perinatal depressive symptoms on children's brains. A search on PubMed and Embase of structural, functional Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) studies exploring the effect of PND on offspring's brain was conducted. We selected twenty-six studies, ten structural MRI, five DTI, six fMRI and five with combined techniques. Overall, the studies showed: a) gray matter alterations in amygdala and fronto-temporal lobes; b) microstructural alterations in amygdala, frontal lobe, cingulum, longitudinal fasciculus and fornix; and c) functional alterations between limbic and mesocortical networks. The small sample size and the heterogeneity in populations and methodologies limit this review. In conclusion, PND seems to influence structure and function of offspring, that may contribute to the risk of behavioral disturbances later in life.

Learning interpretable cellular and gene signature embeddings from single-cell transcriptomic data

The advent of single-cell RNA sequencing (scRNA-seq) technologies has revolutionized transcriptomic studies. However, large-scale integrative analysis of scRNA-seq data remains a challenge largely due to unwanted batch effects and the limited transferabilty, interpretability, and scalability of the existing computational methods. We present single-cell Embedded Topic Model (scETM). Our key contribution is the utilization of a transferable neural-network-based encoder while having an interpretable linear decoder via a matrix tri-factorization. In particular, scETM simultaneously learns an encoder network to infer cell type mixture and a set of highly interpretable gene embeddings, topic embeddings, and batch-effect linear intercepts from multiple scRNA-seq datasets. scETM is scalable to over 106 cells and confers remarkable cross-tissue and cross-species zero-shot transfer-learning performance. Using gene set enrichment analysis, we find that scETM-learned topics are enriched in biologically meaningful and disease-related pathways. Lastly, scETM enables the incorporation of known gene sets into the gene embeddings, thereby directly learning the associations between pathways and topics via the topic embeddings.

Impact of prenatal stress on amygdala anatomy in young adulthood: Timing and location matter

BACKGROUND

Exposure to maternal stress in utero has long-term implications for the developing brain and has been linked with a higher risk of depression. The amygdala, which develops during the early embryonic stage and is critical for emotion processing, might be particularly sensitive.

METHODS

Using data from a neuroimaging follow-up of the ELSPAC prenatal birth cohort (n=129, 47% men, 23-24 years old), we studied the impact of prenatal stress during the first and second half of pregnancy on the volume of the amygdala and its nuclei in young adult offspring. We further evaluated the relationship between amygdala anatomy and offspring depressive symptomatology. Amygdala nuclei were parcellated using FreeSurfer's automated segmentation pipeline. Depressive symptoms were measured via self-report using the Beck Depression Inventory (BDI).

RESULTS

Exposure to stress during the first half of pregnancy was associated with smaller accessory basal (Cohen's f²=0.27, p(FDR)=0.03) and cortical (Cohen's f²=0.29, p(FDR)=0.03) nuclei volumes. This effect remained significant after correcting for sex, stress during the second half of pregnancy, as well as maternal age at birth, birth weight, maternal education, and offspring's age at MRI. These two nuclei showed a quadratic relationship with BDI scores in young adulthood, where both smaller and larger volume was associated with more depressive symptoms (Accessory basal nucleus: Adj R²=0.05. p(FDR)=0.015; Cortical nucleus: Adj R²=0.04, p(FDR)=0.015).

CONCLUSIONS

We conclude that exposure to stress during the first half of pregnancy might have long-term implications for amygdala anatomy, which may in turn predict the experience of depressive symptoms in young adulthood.

Clinically depressed and typically developing mother-infant dyads: Domain base rates and correspondences, relationship contingencies and attunement

Maternal depression is associated with adverse outcomes in infants. Unfavorable parenting practices likely constitute one pathway of risk transmission from mother to infant, but definitional and methodological variation in the extant literature precludes a comprehensive or conclusive understanding of potential underlying mechanisms. This study aimed to illuminate the role of maternal clinical depression in mother-infant interaction by turning a microanalytic lens on four substantive relationship issues: base rates, correspondences, contingencies, and attunement. Several maternal parenting practices (aggregated into social, didactic, and language domains) and several infant behaviors (aggregated into social, exploration, and non-distress vocalization domains) were microcoded to 0.10 s from naturalistic hour long interactions of clinically depressed mothers (n = 60) and matched non-depressed controls (n = 60) with their 5-month-olds. Clinically depressed mothers spontaneously engaged their infants less didactically, were less contingent to their infants in social, didactic, and language domains, and were less attuned with their infants than were non-depressed mothers. Infants of clinically depressed mothers vocalized non-distress less than infants of non-depressed mothers. These differences unveil key disadvantages in the everyday lived experiences of infants of clinically depressed mothers. The findings advance understanding of maternal depression and its effects and have implications for identifying infants at risk on account of their mothers' clinical depression.

Cord blood DNA methylation modifications in infants are associated with white matter microstructure in the context of prenatal maternal depression and anxiety

Maternal and environmental factors influence brain networks and architecture via both physiological pathways and epigenetic modifications. In particular, prenatal maternal depression and anxiety symptoms appear to impact infant white matter (WM) microstructure, leading us to investigate whether epigenetic modifications (i.e., DNA methylation) contribute to these WM differences. To determine if infants of women with depression and anxiety symptoms exhibit epigenetic modifications linked to neurodevelopmental changes, 52 umbilical cord bloods (CBs) were profiled. We observed 219 differentially methylated genomic positions (DMPs; FDR p < 0.05) in CB that were associated with magnetic resonance imaging measures of WM microstructure at 1 month of age and in regions previously described to be related to maternal depression and anxiety symptoms. Genomic characterization of these associated DMPs revealed 143 unique genes with significant relationships to processes involved in neurodevelopment, GTPase activity, or the canonical Wnt signaling pathway. Separate regression models for female (n = 24) and male (n = 28) infants found 142 associated DMPs in females and 116 associated DMPs in males (nominal p value < 0.001, R > 0.5), which were annotated to 98 and 81 genes, respectively. Together, these findings suggest that umbilical CB DNA methylation levels at birth are associated with 1-month WM microstructure.

Maternal Adverse Childhood Experience and Depression in Relation with Brain Network Development and Behaviors in Children: A Longitudinal Study

Maternal childhood maltreatment and depression increase risks for the psychopathology of the offspring. This study employed a longitudinal dataset of mother-child dyads to investigate the developmental trajectories of brain functional networks and behaviors of children in relation with maternal childhood adverse experience and depression. Maternal childhood trauma was retrospectively assessed via childhood trauma questionnaire, whereas maternal depressive symptoms were prospectively evaluated during pregnancy and after delivery (n = 518). Child brain scans were acquired at age of 4.5, 6, and 7.5 years (n = 163) and behavioral problems were measured at 7.5 years using the Child Behavior Checklist. We found the functional connectivity of the language network with the sensorimotor, frontal, and attentional networks as a function of maternal adverse experience that interacted with sex and age. Girls exposed to mothers with depressive symptoms or childhood abuse showed the increased development of the functional connectivity of the language network with the visual networks, which was associated with social problems. Girls exposed to mothers with depressive symptoms showed the slower growth of the functional connectivity of the language network with the sensorimotor networks. Our findings, in a community sample, suggest the language network organization as neuroendophenotypes for maternal childhood trauma and depression.

[Formula: see text] Neural correlates of socioeconomic status in early childhood: a systematic review of the literature

It is now established that socioeconomic variables are associated with cognitive, academic achievement, and psychiatric outcomes. Recent years have shown the advance in our understanding of how socioeconomic status (SES) relates to brain development in the first years of life (ages 0-5 years). However, it remains unknown which neural structures and functions are most sensitive to the environmental experiences associated with SES. Pubmed, PsycInfo, and Google Scholar databases from January 1, 2000, to December 31, 2019, were systematically searched using terms "Neural" OR "Neuroimaging" OR "Brain" OR "Brain development," AND "Socioeconomic" OR "SES" OR "Income" OR "Disadvantage" OR "Education," AND "Early childhood" OR "Early development". Nineteen studies were included in the full review after applying all exclusion criteria. Studies revealed associations between socioeconomic and neural measures and indicated that, in the first years of life, certain neural functions and structures (e.g., those implicated in language and executive function) may be more sensitive to socioeconomic context than others. Findings broadly support the hypothesis that SES associations with neural structure and function operate on a gradient. Socioeconomic status is reflected in neural architecture and function of very young children, as early as shortly after birth, with its effects possibly growing throughout early childhood as a result of postnatal experiences. Although socioeconomic associations with neural measures were relatively consistent across studies, results from this review are not conclusive enough to supply a neural phenotype of low SES. Further work is necessary to understand causal mechanisms underlying SES-brain associations.

Canonical TGF-β signaling regulates the relationship between prenatal maternal depression and amygdala development in early life

Canonical transforming growth factor-beta (TGF-β) signaling exerts neuroprotection and influences memory formation and synaptic plasticity. It has been considered as a new target for the prevention and treatment of depression. This study aimed to examine its modulatory role in linking prenatal maternal depressive symptoms and the amygdala volumes from birth to 6 years of age. We included mother-child dyads (birth: n = 161; 4.5 years: n = 131; 6 years: n = 162) and acquired structural brain images of children at these three time points. Perinatal maternal depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS) questionnaire to mothers at 26 weeks of pregnancy and 3 months postpartum. Our findings showed that the genetic variants of TGF-β type I transmembrane receptor (TGF-βRI) modulated the association between prenatal maternal depressive symptoms and the amygdala volume consistently from birth to 6 years of age despite a trend of significance at 4.5 years of age. Children with a lower gene expression score (GES) of TGF-βRI exhibited larger amygdala volumes in relation to greater prenatal maternal depressive symptoms. Moreover, children with a lower GES of the TGF-β type II transmembrane receptor (TGF-βRII), Smad4, and Smad7 showed larger amygdala volumes at 6 years of age in relation to greater prenatal maternal depressive symptoms. These findings support the involvement of the canonical TGF-β signaling pathway in the brain development of children in the context of in utero maternal environment. Such involvement is age-dependent.

Maternal Distress and Offspring Neurodevelopment: Challenges and Opportunities for Pre-clinical Research Models

Pre-natal exposure to acute maternal trauma or chronic maternal distress can confer increased risk for psychiatric disorders in later life. Acute maternal trauma is the result of unforeseen environmental or personal catastrophes, while chronic maternal distress is associated with anxiety or depression. Animal studies investigating the effects of pre-natal stress have largely used brief stress exposures during pregnancy to identify critical periods of fetal vulnerability, a paradigm which holds face validity to acute maternal trauma in humans. While understanding these effects is undoubtably important, the literature suggests maternal stress in humans is typically chronic and persistent from pre-conception through gestation. In this review, we provide evidence to this effect and suggest a realignment of current animal models to recapitulate this chronicity. We also consider candidate mediators, moderators and mechanisms of maternal distress, and suggest a wider breadth of research is needed, along with the incorporation of advanced -omics technologies, in order to understand the neurodevelopmental etiology of psychiatric risk.

The placental lipidome of maternal antenatal depression predicts socio-emotional problems in the offspring

While maternal mental health strongly influences neurodevelopment and health in the offspring, little is known about the determinants of inter-individual variation in the mental health of mothers. Likewise, the in utero biological pathways by which variation in maternal mental health affects offspring development remain to be defined. Previous studies implicate lipids, consistent with a known influence on cognitive and emotional function, but the relevance for maternal mental health and offspring neurodevelopment is unclear. This study characterizes the placental and circulatory lipids in antenatal depression, as well as socio-emotional outcomes in the offspring. Targeted liquid chromatography-mass spectrometry covering 470 lipid species was performed on placenta from 186 women with low (n = 70) or high (n = 116) levels of antenatal depressive symptoms assessed using the Edinburgh Postnatal Depression Scale at 26 weeks' gestation. Child socio-emotional outcomes were assessed from the Child Behavior Check List (CBCL) at 48 months. Seventeen placental lipid species showed an inverse association with antenatal EPDS scores. Specifically, lower levels of phospholipids containing LC-PUFAs: omega-3 docosapentaenoic acid (DPA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-6 arachidonic acid (AA) were significantly associated with depressive symptoms. Additional measurement of LC-PUFA in antenatal plasma samples at mid-gestation confirmed the reduced circulation of these specific fatty acids in mothers. Reduced concentration of the placental phospholipids also predicted poorer socio-emotional outcomes in the offspring. This study provides new insights into the role of the materno-fetal lipid cross-talk as a mechanism linking maternal mental health to that of the offspring. These findings show the potential utility of nutritional approaches among pregnant women with depressive symptoms to reduce offspring risk for later socio-emotional problems.

Depression, obesity and their comorbidity during pregnancy: effects on the offspring's mental and physical health

Depression and obesity represent two of the most common complications during pregnancy and are associated with severe health risks for both the mother and the child. Although several studies have analysed the individual effects of depression or obesity on the mothers and their children, the effects associated with the co-occurrence of both disorders have so far been poorly investigated. The relationship between depression and obesity is very complex and it is still unclear whether maternal depression leads to obesity or vice versa. It is well known that the intrauterine environment plays an important role in mediating the effects of both depression and obesity in the mother on the fetal programming, increasing the child's risk to develop negative outcomes.

Do intrinsic brain functional networks predict working memory from childhood to adulthood?

Working memory (WM) is defined as the ability to maintain a representation online to guide goal‐directed behavior. Its capacity in early childhood predicts academic achievements in late childhood and its deficits are found in various neurodevelopmental disorders. We employed resting‐state fMRI (rs‐fMRI) of 468 participants aged from 4 to 55 years and connectome‐based predictive modeling (CPM) to explore the potential predictive power of intrinsic functional networks to WM in preschoolers, early and late school‐age children, adolescents, and adults. We defined intrinsic functional networks among brain regions identified by activation likelihood estimation (ALE) meta‐analysis on existing WM functional studies (ALE‐based intrinsic functional networks) and intrinsic functional networks generated based on the whole brain (whole‐brain intrinsic functional networks). We employed the CPM on these networks to predict WM in each age group. The CPM using the ALE‐based and whole‐brain intrinsic functional networks predicted WM of individual adults, while the prediction power of the ALE‐based intrinsic functional networks was superior to that of the whole‐brain intrinsic functional networks. Nevertheless, the CPM using the whole‐brain but not the ALE‐based intrinsic functional networks predicted WM in adolescents. And, the CPM using neither the ALE‐based nor whole‐brain networks predicted WM in any of the children groups. Our findings showed the trend of the prediction power of the intrinsic functional networks to cognition in individuals from early childhood to adulthood.

Maternal antenatal depression and child mental health: Moderation by genomic risk for attention-deficit/hyperactivity disorder

Maternal antenatal depression strongly influences child mental health but with considerable inter-individual variation that is, in part, linked to genotype. The challenge is to effectively capture the genotypic influence. We outline a novel approach to describe genomic susceptibility to maternal antenatal depression focusing on child emotional/behavioral difficulties. Two cohorts provided measures of maternal depression, child genetic variation, and child mental health symptoms. We constructed a conventional polygenic risk score (PRS) for attention-deficit/hyperactivity disorder (ADHD) (PRSADHD) that significantly moderated the association between maternal antenatal depression and internalizing problems at 60 months (p = 2.94 × 10-4, R2 = .18). We then constructed an interaction PRS (xPRS) based on a subset of those single nucleotide polymorphisms from the PRSADHD that most accounted for the moderation of the association between maternal antenatal depression and child outcome. The interaction between maternal antenatal depression and this xPRS accounted for a larger proportion of the variance in child emotional/behavioral problems than models based on any PRSADHD (p = 5.50 × 10-9, R2 = .27), with similar findings in the replication cohort. The xPRS was significantly enriched for genes involved in neuronal development and synaptic function. Our study illustrates a novel approach to the study of genotypic moderation on the impact of maternal antenatal depression on child mental health and highlights the utility of the xPRS approach. These findings advance our understanding of individual differences in the developmental origins of mental health.

Disrupted intrinsic functional brain topology in patients with major depressive disorder

Aberrant topological organization of whole-brain networks has been inconsistently reported in studies of patients with major depressive disorder (MDD), reflecting limited sample sizes. To address this issue, we utilized a big data sample of MDD patients from the REST-meta-MDD Project, including 821 MDD patients and 765 normal controls (NCs) from 16 sites. Using the Dosenbach 160 node atlas, we examined whole-brain functional networks and extracted topological features (e.g., global and local efficiency, nodal efficiency, and degree) using graph theory-based methods. Linear mixed-effect models were used for group comparisons to control for site variability; robustness of results was confirmed (e.g., multiple topological parameters, different node definitions, and several head motion control strategies were applied). We found decreased global and local efficiency in patients with MDD compared to NCs. At the nodal level, patients with MDD were characterized by decreased nodal degrees in the somatomotor network (SMN), dorsal attention network (DAN) and visual network (VN) and decreased nodal efficiency in the default mode network (DMN), SMN, DAN, and VN. These topological differences were mostly driven by recurrent MDD patients, rather than first-episode drug naive (FEDN) patients with MDD. In this highly powered multisite study, we observed disrupted topological architecture of functional brain networks in MDD, suggesting both locally and globally decreased efficiency in brain networks.

Individual, Prenatal, Perinatal, and Family Factors for Anxiety Symptoms Among Preschool Children

Anxiety is one of the most common psychological disorders among children. Few studies have investigated the prevalence and comprehensive factors for anxiety among preschool children in China. This study aimed to assess the prevalence of anxiety and explore influential factors at multiple levels including individual, prenatal and perinatal, and family factors, associated with anxiety symptoms among preschool children. The multisite cross-sectional study was conducted in Anhui Province and included 3,636 preschool children aged 3-6 years. Anxiety symptoms of children were assessed using the Chinese version of the Spence Preschool Anxiety Scale. Logistic regression analyses were performed to explore associations between factors at multiple levels and significant anxiety symptoms, and the model was validated internally using 10-fold cross-validation. Among the participants, 9.1% of children had significant anxiety symptoms. Girls reported more significant anxiety symptoms. Children's poor dietary habits, sleep disturbances, autistic tendencies, and left-behind experience; maternal poor prenatal emotional symptoms; and more caregivers' anxiety symptoms were significantly associated with anxiety symptoms among children. The result of 10-fold cross-validation indicated that the mean area under the curve, sensitivity, specificity, and accuracy were 0.78, 70.45%, 78.18%, and 71.15%, respectively. These factors were slightly different among different subtypes of anxiety symptoms. The results of this study suggested that anxiety symptoms in preschool children were prevalent, particularly in girls. Understanding early-life risk factors for anxiety is crucial, and efficient prevention and intervention strategies should be implemented in early childhood even pregnancy.

Preconception origins of perinatal maternal mental health

Perinatal maternal symptoms of depression and anxiety compromise psychosocial function and influence developmental outcomes in the offspring. The onset of symptoms remains unclear with findings that suggest a preconceptual origin. We addressed this issue with a prospective analysis of anxiety and depressive symptom profiles from preconception through to parturition. Women were recruited into a preconception study to assess (a) variation in symptom levels of depression and anxiety from pre- to post-conception and (b) if the symptom network profiles of depression and anxiety change from pre-conception to post-conception. A within-subject intraclass correlation analyses revealed that symptoms of depression or anxiety in the preconception phase strongly predicted those across pregnancy and into the early postnatal period. The symptom network analysis revealed that the symptom profiles remained largely unchanged from preconception into the second trimester. Our findings suggest that for a significant portion of women, maternal mental health remains stable from preconception into pregnancy. This finding highlights the need for early intervention studies on women's mental health to be targeted during the preconception period and to be extended across the population.

Inflammatory modulation of the associations between prenatal maternal depression and neonatal brain

Inflammatory signaling has a role in sensing intrauterine environment, which may be moderators in altering fetal brain development upon maternal environment. This study integrated cytokine transcriptome of post-mortem fetal brains, neonatal brain imaging and genetic variants (n = 161) to examine whether cytokines are candidates for modulating the relationship between prenatal maternal depression and fetal brain development. This study obtained the transcriptome data of 208 cytokine genes in 12 fetal brain regions from the BrainSpan database. We also included 161 mother-child dyads with prenatal maternal depressive symptoms assessed at 26 weeks of gestation, cytokine genotype data extracted from umbilical cord specimens, and neonatal brain images from a longitudinal prospective birth cohort. We revealed that 22 cytokine genes are expressed in specific brain regions in utero, whose variants have roles in modulating the effects of the prenatal environment on the accelerated fetal development of the hippocampus, auditory, parietal, orbitofrontal, and dorsal prefrontal cortex. Neonates high in the genetic expression score (GES) of TNFRSF19 and IL17RB showed a larger right hippocampal volume, high in the GES of BMPR1B showed the thicker thickness of the sensorimotor cortex, and high in the GES of IL1RAP and CXCR4 demonstrated the thicker thickness of the dorsal and orbital prefrontal cortex in relation with greater prenatal maternal depressive symptoms. Our findings suggest that in humans, the cytokine genes are expressed in a brain region-specific manner in utero and may have potential roles in modulating the fetal development of the corresponding brain regions in response to the maternal environment.

Application of a diathesis-stress model to the interplay of cortical structural development and emerging depression in youth

Cross-sectional studies in adults have long identified differences in cortical structure in adults with depression compared to healthy adults, with most studies identifying reductions in grey matter volume, cortical thickness, and surface area in primarily frontal cortical regions including the OFC, ACC, and variable sub-regions of the PFC. However, when, why, and for whom these neural correlates of depression emerge remains poorly understood, necessitating developmental study of associations between depression and cortical structure. We systematically reviewed studies examining these associations in child/adolescent samples, and applied a developmentally-focused diathesis-stress model to understand the impacts of depressogenic risk-factors and stressors on the development of structural neural correlates of depression. Cross-sectional findings in youth are generally similar to those found in adults, but vary in magnitude and direction of effects. Preliminary evidence suggests that age, sex, severity, and comorbidity moderate these associations. Longitudinal studies show depression prospectively predicting cortical structure and structure predicting emerging depression. Consistent with a diathesis-stress model, associations have been noted between risk-factors for depression (e.g., genetic risk, family risk) and environmental stressors (e.g., early life stress) and structural neural correlates. Further investigation of these associations across development with attention to vulnerability factors and stressors is indicated.

Maternal influences on fetal brain development: The role of nutrition, infection and stress, and the potential for intergenerational consequences

An optimal early life environment is crucial for ensuring ideal neurodevelopmental outcomes. Brain development consists of a finely tuned series of spatially and temporally constrained events, which may be affected by exposure to a sub-optimal intra-uterine environment. Evidence suggests brain development may be particularly vulnerable to factors such as maternal nutrition, infection and stress during pregnancy. In this review, we discuss how maternal factors such as these can affect brain development and outcome in offspring, and we also identify evidence which suggests that the outcome can, in many cases, be stratified by socio-economic status (SES), with individuals in lower brackets typically having a worse outcome. We consider the relevant epidemiological evidence and draw parallels to mechanisms suggested by preclinical work where appropriate. We also discuss possible transgenerational effects of these maternal factors and the potential mechanisms involved. We conclude that modifiable factors such as maternal nutrition, infection and stress are important contributors to atypical brain development and that SES also likely has a key role.

Prenatal maternal depressive symptoms are associated with smaller amygdalar volumes of four-year-old children

Prenatal maternal depressive symptoms are related to an increased offspring susceptibility to psychiatric disorders over the life course. Alterations in fetal brain development might partly mediate this association. The relation of prenatal depressive symptoms with child's amygdalar volumes is still underexplored, and this study aimed to address this gap. We explored the association of prenatal maternal depressive symptoms with amygdalar volumes in 28 4-year-old children (14 female). Amygdalar volumes were assessed using the volBrain pipeline and manual segmentation. Prenatal depressive symptoms were self-reported by mothers at gestational weeks 14, 24 and 34 (Edinburgh Postnatal Depression Scale). Sex differences were probed, and possible pre- and postnatal confounders, such as maternal general anxiety, were controlled for. We observed that elevated depressive symptoms of the early second trimester, after controlling for prenatal maternal general anxiety, were significantly related to smaller right amygdalar volumes in the whole sample. Higher depressive symptoms of the third trimester were associated with significantly smaller right amygdalar volumes in boys compared to girls. Altogether, our data suggest that offspring limbic brain development might be affected by maternal depressive symptoms in early pregnancy, and might also be more vulnerable to depressive symptoms in late pregnancy in boys compared to girls.

Neonatal hippocampal volume moderates the effects of early postnatal enrichment on cognitive development

Environmental enrichment, particularly during the early life phases of enhanced neuroplasticity, can stimulate cognitive development. However, individuals exhibit considerable variation in their response to environmental enrichment. Recent evidence suggests that certain neurophenotypes such as hippocampal size may index inter-individual differences in sensitivity to environmental conditions. We conducted a prospective, longitudinal investigation in a cohort of 75 mother-child dyads to investigate whether neonatal hippocampal volume moderates the effects of the postnatal environment on cognitive development. Newborn hippocampal volume was quantified shortly after birth (26.2 ± 12.5 days) by structural MRI. Measures of infant environmental enrichment (assessed by the IT-HOME) and cognitive state (assessed by the Bayley-III) were obtained at 6 months of age (6.09 ± 1.43 months). The interaction between neonatal hippocampal volume and enrichment predicted infant cognitive development (b = 0.01, 95 % CI [0.00, 0.02], t = 2.08, p = .04), suggesting that exposure to a stimulating environment had a larger beneficial effect on cognitive outcomes among infants with a larger hippocampus as neonates. Our findings suggest that the effects of the postnatal environment on infant cognitive development are conditioned, in part, upon characteristics of the newborn brain, and that newborn hippocampal volume is a candidate neurophenotype in this context.

Environmental epigenetics of sex differences in the brain

Experiences throughout the life course lead to unique phenotypes even among those with the same genotype. Genotype sets the substrate on which physiologic processes, which communicate with the brain, mediate the effects of life experiences via epigenetics. Epigenetics modify the expression of genes in the brain and body in response to circulating hormones and other mediators, which are activated to facilitate survival responses through a process called allostasis. Epigenetic signatures can even be inherited, resulting in transgenerational effects. This chapter addresses epigenetics in the context of sex differences, discussing the intersection between genetics and gonadal hormones and their effect in the brain at discrete developmental periods.

Sex-specific association between infant caudate volumes and a polygenic risk score for major depressive disorder

Polygenic risk scores for major depressive disorder (PRS-MDD) have been identified in large genome-wide association studies, and recent findings suggest that PRS-MDD might interact with environmental risk factors to shape human limbic brain development as early as in the prenatal period. Striatal structures are crucially involved in depression; however, the association of PRS-MDD with infant striatal volumes is yet unknown. In this study, 105 Finnish mother-infant dyads (44 female, 11-54 days old) were investigated to reveal how infant PRS-MDD is associated with infant dorsal striatal volumes (caudate, putamen) and whether PRS-MDD interacts with prenatal maternal depressive symptoms (Edinburgh Postnatal Depression Scale, gestational weeks 14, 24, 34) on infant striatal volumes. A robust sex-specific main effect of PRS-MDD on bilateral infant caudate volumes was observed. PRS-MDD were more positively associated with caudate volumes in boys compared to girls. No significant interaction effects of genotype PRS-MDD with the environmental risk factor "prenatal maternal depressive symptoms" (genotype-by-environment interaction) nor significant interaction effects of genotype with prenatal maternal depressive symptoms and sex (genotype-by-environment-by-sex interaction) were found for infant dorsal striatal volumes. Our study showed that a higher PRS-MDD irrespective of prenatal exposure to maternal depressive symptoms is associated with smaller bilateral caudate volumes, an indicator of greater susceptibility to major depressive disorder, in female compared to male infants. This sex-specific polygenic effect might lay the ground for the higher prevalence of depression in women compared to men.

Newborn amygdalar volumes are associated with maternal prenatal psychological distress in a sex-dependent way

Maternal psychological distress during pregnancy (PPD)1 has been associated with changes in offspring amygdalar and hippocampal volumes. Studies on child amygdalae suggest that sex moderates the vulnerability of fetal brains to prenatal stress. However, this has not yet been observed in these structures in newborns. Newborn studies are crucial, as they minimize the confounding influence of postnatal life. We investigated the effects of maternal prenatal psychological symptoms on newborn amygdalar and hippocampal volumes and their interactions with newborn sex in 123 newborns aged 2-5 weeks (69 males, 54 females). Based on earlier studies, we anticipated small, but statistically significant effects of PPD on the volumes of these structures. Maternal psychological distress was measured at gestational weeks (GW)2 14, 24 and 34 using Symptom Checklist-90 (SCL-90, anxiety scale)3 and Edinburgh Postnatal Depression Scale (EPDS)4 questionnaires. Newborn sex was found to moderate the relationship between maternal distress symptoms at GW 24 and the volumes of left and right amygdala. This relationship was negative and significant only in males. No significant main effect or sex-based moderation was found for hippocampal volumes. This newborn study provides evidence for a sex-dependent influence of maternal psychiatric symptoms on amygdalar structural development. This association may be relevant to later psychopathology.