Amygdala-Prefrontal Structural Connectivity Mediates the Relationship between Prenatal Depression and Behavior in Preschool Boys

Prenatal stress and externalizing behaviors in childhood and adolescence: A systematic review and meta-analysis

Accumulating evidence suggests that psychological distress during pregnancy is linked to offspring risk for externalizing outcomes (e.g., reactive/aggressive behaviors, hyperactivity, and impulsivity). Effect sizes across studies have varied widely, however, due to differences in study design and methodology, including control for the confounding continuation of distress in the postnatal period. Clarifying these inconsistencies is necessary to guide the precision of prevention efforts and inform public health policies. A meta-analysis was conducted with 55 longitudinal studies to investigate the association between prenatal psychological distress (anxiety, depression, and perceived stress) and offspring externalizing behaviors. Results revealed a significant but small effect (r = .160) of prenatal distress on externalizing behaviors. The magnitude of the prenatal effect size remained largely unchanged after adjusting for postnatal distress (r = .159), implicating a unique effect of psychological distress during the prenatal period in the etiology of externalizing behaviors. Moderation tests showed that prenatal effects did not vary based on type and timing of psychological distress during pregnancy. Greater instability of distress from prenatal to postnatal periods predicted larger effects. Prenatal effects were comparable across most externalizing outcomes, consistent with the common comorbidity of externalizing spectrum disorders, although effects appeared smaller for nonaggressive rule-breaking (vs. aggressive) behaviors. Significant associations persisted across all developmental periods, appearing slightly larger in early childhood. We discuss these results in the context of developmental and psychobiological theories of externalizing behavior, offer preliminary clinical and public health implications, and highlight directions for future research including the need for longitudinal studies with more racially and socioeconomically diverse families. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The effects of experience of discrimination and acculturation during pregnancy on the developing offspring brain

The experience of ethnic, racial, and structural inequalities is increasingly recognized as detrimental to health, and early studies suggest that its experience in pregnant mothers may affect the developing fetus. We characterized discrimination and acculturation experiences in a predominantly Hispanic sample of pregnant adolescent women and assessed their association with functional connectivity in their neonate's brain. We collected self-report measures of acculturation, discrimination, maternal distress (i.e., perceived stress, childhood trauma, and depressive symptoms), and socioeconomic status in 165 women. Then, we performed a data-driven clustering of acculturation, discrimination, perceived stress, depressive symptoms, trauma, and socioeconomic status variables during pregnancy to determine whether discrimination or acculturation clustered into distinct factors. Discrimination and acculturation styles loaded onto different factors from perceived stress, depressive symptoms, trauma, and socioeconomic status, suggesting that they were distinct from other factors in our sample. We associated these data-driven maternal phenotypes (discrimination and acculturation styles) with measures of resting-state functional MRI connectivity of the infant amygdala (n = 38). Higher maternal report of assimilation was associated with weaker connectivity between their neonate's amygdala and bilateral fusiform gyrus. Maternal experience of discrimination was associated with weaker connectivity between the amygdala and prefrontal cortex and stronger connectivity between the amygdala and fusiform of their neonate. Cautiously, the results may suggest a similarity to self-contained studies with adults, noting that the experience of discrimination and acculturation may influence amygdala circuitry across generations. Further prospective studies are essential that consider a more diverse population of minoritized individuals and with a comprehensive assessment of ethnic, racial, and structural factors.

Prenatal and Postnatal Maternal Depressive Symptoms Are Associated With White Matter Integrity in 5-Year-Olds in a Sex-Specific Manner

BACKGROUND

Prenatal and postnatal maternal psychological distress predicts various detrimental consequences on social, behavioral, and cognitive development of offspring, especially in girls. Maturation of white matter (WM) continues from prenatal development into adulthood and is thus susceptible to exposures both before and after birth.

METHODS

WM microstructural features of 130 children (mean age, 5.36 years; range, 5.04-5.79 years; 63 girls) and their association with maternal prenatal and postnatal depressive and anxiety symptoms were investigated with diffusion tensor imaging, tract-based spatial statistics, and regression analyses. Maternal questionnaires were collected during first, second, and third trimesters and at 3, 6, and 12 months postpartum with the Edinburgh Postnatal Depression Scale (EPDS) for depressive symptoms and Symptom Checklist-90 for general anxiety. Covariates included child's sex; child's age; maternal prepregnancy body mass index; maternal age; socioeconomic status; and exposures to smoking, selective serotonin reuptake inhibitors, and synthetic glucocorticoids during pregnancy.

RESULTS

Prenatal second-trimester EPDS scores were positively associated with fractional anisotropy in boys (p < .05, 5000 permutations) after controlling for EPDS scores 3 months postpartum. In contrast, postpartum EPDS scores at 3 months correlated negatively with fractional anisotropy (p < .01, 5000 permutations) in widespread areas only in girls after controlling for prenatal second-trimester EPDS scores. Perinatal anxiety was not associated with WM structure.

CONCLUSIONS

These results suggest that prenatal and postnatal maternal psychological distress is associated with brain WM tract developmental alterations in a sex- and timing-dependent manner. Future studies including behavioral data are required to consolidate associative outcomes for these alterations.

Adolescents at risk for depression show increased white matter microstructure with age across diffuse areas of the brain

Maternal history of depression is a strong predictor of depression in offspring and linked to structural and functional alterations in the developing brain. However, very little work has examined differences in white matter in adolescents at familial risk for depression. In a sample aged 9-14 (n = 117), we used tract-based spatial statistics (TBSS) to examine differences in white matter microstructure between adolescents with (n = 42) and without (n = 75) maternal history of depression. Microstructure was indexed using fractional anisotropy (FA). Threshold-free cluster enhancement was applied and cluster maps were thresholded at whole-brain family-wise error < .05. There was no significant main effect of risk status on FA. However, there was a significant interaction between risk status and age, such that large and diffuse portions of the white matter skeleton showed relatively increased FA with age for youth with a maternal history of depression compared to those without. Most tracts identified by the interaction were robust to controlling for sex, youth internalizing, in-scanner motion, neighborhood SES, and intra-cranial volume, evidence that maternal depression is a unique predictor of white matter alterations in youth. Widespread increases in FA with age may correspond to a global pattern of accelerated brain maturation in youth at risk for depression.

Maternal anxiety during pregnancy is associated with weaker prefrontal functional connectivity in adult offspring

BACKGROUND

The connectome, constituting a unique fingerprint of a person's brain, may be influenced by its prenatal environment, potentially affecting later-life resilience and mental health.

METHODS

We conducted a prospective resting-state functional Magnetic Resonance Imaging study in 28-year-old offspring (N = 49) of mothers whose anxiety was monitored during pregnancy. Two offspring anxiety subgroups were defined: "High anxiety" (n = 13) group versus "low-to-medium anxiety" (n = 36) group, based on maternal self-reported state anxiety at 12-22 weeks of gestation. To predict resting-state functional connectivity of 32 by 32 ROIs, maternal state anxiety during pregnancy was included as a predictor in general linear models for both ROI-to-ROI and graph theoretical metrics. Sex, birth weight and postnatal anxiety were included as covariates.

RESULTS

Higher maternal anxiety was associated with weaker functional connectivity of medial prefrontal cortex with left inferior frontal gyrus (t = 3.45, pFDR < 0.05). Moreover, network-based statistics (NBS) confirmed our finding and revealed an additional association of weaker connectivity between left lateral prefontal cortex with left somatosensory motor gyrus in the offspring. While our results showed a general pattern of lower functional connectivity in adults prenatally exposed to maternal anxiety, we did not observe significant differences in global brain networks between groups.

CONCLUSIONS

Weaker (medial) prefrontal cortex functional connectivity in the high anxiety adult offspring group suggests a long-term negative impact of prenatal exposure to high maternal anxiety, extending into adulthood. To prevent mental health problems at population level, universal primary prevention strategies should aim at lowering maternal anxiety during pregnancy.

Brain-based Sex Differences in Depression: A Systematic Review of Neuroimaging Studies

Major depressive disorder (MDD) is a common psychiatric illness with a wide range of symptoms such as mood decline, loss of interest, and feelings of guilt and worthlessness. Women develop depression more often than men, and the diagnostic criteria for depression mainly rely on female patients' symptoms. By contrast, male depression usually manifests as anger attacks, aggression, substance use, and risk-taking behaviors. Various studies have focused on the neuroimaging findings in psychiatric disorders for a better understanding of their underlying mechanisms. With this review, we aimed to summarize the existing literature on the neuroimaging findings in depression, separated by male and female subjects. A search was conducted on PubMed and Scopus for magnetic resonance imaging (MRI), functional MRI (fMRI), and diffusion tensor imaging (DTI) studies of depression. After screening the search results, 15 MRI, 12 fMRI, and 4 DTI studies were included. Sex differences were mainly reflected in the following regions: 1) total brain, hippocampus, amygdala, habenula, anterior cingulate cortex, and corpus callosum volumes, 2) frontal and temporal gyri functions, along with functions of the caudate nucleus and prefrontal cortex, and 3) frontal fasciculi and frontal projections of corpus callosum microstructural alterations. Our review faces limitations such as small sample sizes and heterogeneity in populations and modalities. But in conclusion, it reflects the possible roles of sex-based hormonal and social factors in the depression pathophysiology.

Prenatal mental health data and birth outcomes in the pregnancy during the COVID-19 Pandemic dataset

The COVID-19 pandemic was a substantial stressor, especially for pregnant individuals. We aimed to understand the impact of COVID-19-related stresses on pregnant individuals and their infants and collected survey-based data across Canada as part of the Pregnancy during the COVID-19 Pandemic (PdP) project. The dataset described here provides baseline prenatal data and basic birth outcomes from PdP participants. This data includes information from pregnant individuals as well as their infants. At enrolment and time of completion of the baseline survey, participants were pregnant, ≥17 years of age, ≤35 weeks of gestation, living in Canada, and able to read and write in English or French. Baseline data were collected between April 2020-April 2021. Infant data were collected between May 2020-December 2021. All data were collected via self-report using online questionnaires in REDCAP. Questionnaires were available in both English and French. Data were checked for completeness and plausibility, and duplicates were removed. The dataset described here includes age, education, and household income of the pregnant individuals reported at the baseline/enrollment survey. Raw scores are provided for the Edinburgh Postnatal Depression Scale (EPDS) and the PROMIS Anxiety scale. Ratings are also given for three variables describing fear of the COVID-19 virus. Birth outcomes are provided for infants, including gestational age at birth, birthweight, length, mode of delivery, and whether the infant spent time in the neonatal intensive care unit (NICU). Delivery date is reported as month and year. These data will be beneficial for anyone interested in researching stress during pregnancy or birth outcomes in the context of the COVID-19 pandemic. They will also be useful to researchers interested in examining more general effects of prenatal distress on birth outcomes in children. Data could also be compared to other datasets from the COVID-19 pandemic to establish generalizability, or to pre-pandemic datasets to determine the extent of changes during the COVID-19 pandemic.

Toward reframing brain-social dynamics: current assumptions and future challenges

Evolutionary analyses suggest that the human social brain and sociality appeared together. The two fundamental tools that accelerated the concurrent emergence of the social brain and sociality include learning and plasticity. The prevailing core idea is that the primate brain and the cortex in particular became reorganised over the course of evolution to facilitate dynamic adaptation to ongoing changes in physical and social environments. Encouraged by computational or survival demands or even by instinctual drives for living in social groups, the brain eventually learned how to learn from social experience via its massive plastic capacity. A fundamental framework for modeling these orchestrated dynamic responses is that social plasticity relies upon neuroplasticity. In the present article, we first provide a glimpse into the concepts of plasticity, experience, with emphasis on social experience. We then acknowledge and integrate the current theoretical concepts to highlight five key intertwined assumptions within social neuroscience that underlie empirical approaches for explaining the brain-social dynamics. We suggest that this epistemological view provides key insights into the ontology of current conceptual frameworks driving future research to successfully deal with new challenges and possible caveats in favour of the formulation of novel assumptions. In the light of contemporary societal challenges, such as global pandemics, natural disasters, violent conflict, and other human tragedies, discovering the mechanisms of social brain plasticity will provide new approaches to support adaptive brain plasticity and social resilience.

Maternal anxiety, exposure to the COVID-19 pandemic and socioemotional development of offspring

The COVID-19 pandemic context may predispose mothers to increased maternal psychopathology, which may be associated with offspring socioemotional development. The aim of this study is to analyze the relationships between prenatal anxiety and depression and exposure to the COVID-19 pandemic with offspring socioemotional development, controlling for postnatal anxiety and depression. A total of 105 mother-child dyads were assessed in pre- and postnatal periods. Questionnaires were used to assess the impact of the pandemic, indicators of psychopathology, and the socioemotional development of the offspring. Results suggest that negative pandemic experiences are indirectly associated with offspring socioemotional development via prenatal maternal anxiety symptomatology and after controlling for postnatal anxiety and depression. These indicators predispose to emotional deficits and increase the risks of psychopathological and neurodevelopmental disorders. It is important to adopt health policies that provide timely assessment of development in early childhood to reduce the risks associated with these deficits.

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.

Prenatal Maternal Distress During the COVID-19 Pandemic and Associations With Infant Brain Connectivity

BACKGROUND

The COVID-19 pandemic has caused substantially elevated distress in pregnant individuals, which has the potential to affect the developing infant brain. Our main objective was to understand how prenatal distress was related to infant brain structure and function and whether social support moderated the associations.

METHODS

The Pregnancy during the COVID-19 Pandemic (PdP) cohort study collected Patient-Reported Outcomes Measurement Information System Anxiety scale, Edinburgh Postnatal Depression Scale, and Social Support Effectiveness Questionnaire data from a population-based sample of pregnant individuals living in Canada (N = 8602). For a subsample of participants, their infants (n = 75) underwent magnetic resonance imaging at 3 months of age to examine whether prenatal maternal distress was associated with infant brain architecture, including the role of social support as a potential protective factor.

RESULTS

Overall, 33.4% of participants demonstrated clinically elevated depression symptoms and 47.1% of participants demonstrated clinically elevated anxiety symptoms. We identified lower social support as a significant predictor of clinically elevated prenatal maternal distress (t8598 = -22.3, p < .001). Fifty-eight diffusion image datasets (20 female/38 male, 92 ± 14 days old) and 41 functional datasets (13 female/28 male, 92 ± 14 days old) were included in our analysis after removal of poor-quality images and infants without postpartum maternal distress scores. We found significant relationships between prenatal maternal distress and infant amygdala-prefrontal microstructural and functional connectivity measures, and we demonstrate for the first time that social support moderates these relationships.

CONCLUSIONS

Our findings suggest a potentially long-lasting impact of the COVID-19 pandemic on children and show that social support acts as a possible mediator not just for pregnant individuals but also developing infants. These findings provide timely evidence to inform clinical practice and policy surrounding the care of pregnant individuals and highlight the importance of social support.

Hypoconnectivity between anterior insula and amygdala associates with future vulnerabilities in social development in a neurodiverse sample of neonates

Altered resting state functional connectivity (FC) involving the anterior insula (aINS), a key node in the salience network, has been reported consistently in autism. Here we examined, for the first time, FC between the aINS and the whole brain in a sample of full-term, postmenstrual age (PMA) matched neonates (mean 44.0 weeks, SD = 1.5) who due to family history have high likelihood (HL) for developing autism (n = 12) and in controls (n = 41) without family history of autism (low likelihood, LL). Behaviors associated with autism were evaluated between 12 and 18 months (M = 17.3 months, SD = 2.5) in a subsample (25/53) of participants using the First Year Inventory (FYI). Compared to LL controls, HL neonates showed hypoconnectivity between left aINS and left amygdala. Lower connectivity between the two nodes was associated with higher FYI risk scores in the social domain (r(25) = -0.561, p = .003) and this association remained robust when maternal mental health factors were considered. Considering that a subsample of LL participants (n = 14/41) underwent brain imaging during the fetal period at PMA 31 and 34 weeks, in an exploratory analysis, we evaluated prospectively development of the LaINS-Lamy connectivity and found that the two areas strongly coactivate throughout the third trimester of pregnancy. The study identifies left lateralized anterior insula-amygdala connectivity as a potential target of further investigation into neural circuitry that enhances likelihood of future onset of social behaviors associated with autism during neonatal and potentially prenatal periods.

Prenatal maternal stress and offspring aggressive behavior: Intergenerational and transgenerational inheritance

Even though studies have shown that prenatal maternal stress is associated with increased reactivity of the HPA axis, the association between prenatal maternal stress and fetal glucocorticoid exposure is complex and most likely dependent on unidentified and poorly understood variables including nature and timing of prenatal insults. The precise mechanisms in which prenatal maternal stress influence neuroendocrine signaling between the maternal-placental-fetal interface are still unclear. The aim of this review article is to bring comprehensive basic concepts about prenatal maternal stress and mechanisms of transmission of maternal stress to the fetus. This review covers recent studies showing associations between maternal stress and alterations in offspring aggressive behavior, as well as the possible pathways for the “transmission” of maternal stress to the fetus: (1) maternal-fetal HPA axis dysregulation; (2) intrauterine environment disruption due to variations in uterine artery flow; (3) epigenetic modifications of genes implicated in aggressive behavior. Here, we present evidence for the phenomenon of intergenerational and transgenerational transmission, to better understands the mechanism(s) of transmission from parent to offspring. We discuss studies showing associations between maternal stress and alterations in offspring taking note of neuroendocrine, brain architecture and epigenetic changes that may suggest risk for aggressive behavior. We highlight animal and human studies that focus on intergenerational transmission following exposure to stress from a biological mechanistic point of view, and maternal stress-induced epigenetic modifications that have potential to impact on aggressive behavior in later generations.

Neonatal frontal-limbic connectivity is associated with externalizing behaviours in toddlers with Congenital Heart Disease

Children with Congenital Heart Disease (CHD) are at increased risk of neurodevelopmental impairments. The neonatal antecedents of impaired behavioural development are unknown. 43 infants with CHD underwent presurgical brain diffusion-weighted MRI [postmenstrual age at scan median (IQR) = 39.29 (38.71-39.71) weeks] and a follow-up assessment at median age of 22.1 (IQR 22.0-22.7) months in which parents reported internalizing and externalizing problem scores on the Child Behaviour Checklist. We constructed structural brain networks from diffusion-weighted MRI and calculated edge-wise structural connectivity as well as global and local brain network features. We also calculated presurgical cerebral oxygen delivery, and extracted perioperative variables, socioeconomic status at birth and a measure of cognitively stimulating parenting. Lower degree in the right inferior frontal gyrus (partial ρ = -0.687, p < 0.001) and reduced connectivity in a frontal-limbic sub-network including the right inferior frontal gyrus were associated with higher externalizing problem scores. Externalizing problem scores were unrelated to neonatal clinical course or home environment. However, higher internalizing problem scores were associated with earlier surgery in the neonatal period (partial ρ = -0.538, p = 0.014). Our results highlight the importance of frontal-limbic networks to the development of externalizing behaviours and provide new insights into early antecedents of behavioural impairments in CHD.

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.

Astrocyte reactivation in medial prefrontal cortex contributes to obesity-promoted depressive-like behaviors

BACKGROUND

Little is known about how the obesogenic environment influences emotional states associated with glial responses and neuronal function. Here, we investigated glial reactivation and neuronal electrophysiological properties in emotion-related brain regions of high-fat diet (HFD) and ob/ob mice under chronic stress.

METHODS

The glial reactivation and neuronal activities in emotion-related brain regions were analyzed among normal diet mice (ND), HFD mice, wild-type mice, and ob/ob mice. To further activate or inhibit astrocytes in medial prefrontal cortex (mPFC), we injected astrocytes specific Gq-AAV or Gi-AAV into mPFC and ongoing treated mice with CNO.

RESULTS

The results showed that obesogenic factors per se had no significant effect on neuronal activities in emotion-related brain regions, or on behavioral performance. However, exposure to a chronic stressor profoundly reduced the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) and spontaneous excitatory postsynaptic currents (sEPSCs) in the mPFC; depressive-like behaviors were seen, accompanied by significant upregulation of astrocyte reactivation. We identified resilient and susceptible mice among chronic social defeat stress-exposed HFD mice. As expected, astrocyte reactivity was upregulated, while neuronal activity was depressed, in the mPFC of susceptible compared to resilient mice. Furthermore, activating astrocytes resulted in similar levels of neuronal activity and depressive-like behaviors between resilient and susceptible mice. Additionally, inhibiting astrocyte reactivation in the mPFC of HFD mice upregulated neuronal activities and inhibited depressive-like behaviors.

CONCLUSIONS

These observations indicate that obesogenic factors increase the risk of depression, and improve our understanding of the pathological relationship between obesity and depression.

Digitalized Cognitive Behavioral Interventions for Depressive Symptoms During Pregnancy: Systematic Review

BACKGROUND

Studies have shown a high prevalence of depression during pregnancy, and there is also evidence that cognitive behavioral therapy (CBT) is one of the most effective psychosocial interventions. Emerging evidence from randomized controlled trials (RCTs) has shown that technology has been successfully harnessed to provide CBT interventions for other populations. However, very few studies have focused on their use during pregnancy. This approach has become increasingly important in many clinical areas due to the COVID-19 pandemic, and our study aimed to expand the knowledge in this particular clinical area.

OBJECTIVE

Our systematic review aimed to bring together the available research-based evidence on digitalized CBT interventions for depression symptoms during pregnancy.

METHODS

A systematic review of the Web of Science, Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE, Embase, PsycINFO, Scopus, ClinicalTrials.gov, and EBSCO Open Dissertations databases was carried out from the earliest available evidence to October 27, 2021. Only RCT studies published in English were considered. The PRISMA (Preferred Reporting Items of Systematic Reviews and Meta-analyses) guidelines were followed, and the protocol was registered on the Prospective Register of Systematic Reviews. The risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials.

RESULTS

The review identified 7 studies from 5 countries (the United States, China, Australia, Norway, and Sweden) published from 2015 to 2021. The sample sizes ranged from 25 to 1342 participants. The interventions used various technological elements, including text, images, videos, games, interactive features, and peer group discussions. They comprised 2 guided and 5 unguided approaches. Using digitalized CBT interventions for depression during pregnancy showed promising efficacy, with guided intervention showing higher effect sizes (Hedges g=1.21) than the unguided interventions (Hedges g=0.14-0.99). The acceptability of the digitalized CBT interventions was highly encouraging, based on user feedback. Attrition rates were low for the guided intervention (4.5%) but high for the unguided interventions (22.1%-46.5%). A high overall risk of bias was present for 6 of the 7 studies.

CONCLUSIONS

Our search only identified a small number of digitalized CBT interventions for pregnant women, despite the potential of this approach. These showed promising evidence when it came to efficacy and positive outcomes for depression symptoms, and user feedback was positive. However, the overall risk of bias suggests that the efficacy of the interventions needs to be interpreted with caution. Future studies need to consider how to mitigate these sources of biases. Digitalized CBT interventions can provide prompt, effective, evidence-based interventions for pregnant women. This review increases our understanding of the importance of digitalized interventions during pregnancy, including during the COVID-19 pandemic.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews CRD42020216159; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=216159.

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.

Change of pace: How developmental tempo varies to accommodate failed provision of early needs

The interplay of genes and environments (GxE) is a fundamental source of variation in behavioral and developmental outcomes. Although the role of developmental time (T) in the unfolding of such interactions has yet to be fully considered, GxE operates within a temporal frame of reference across multiple timescales and degrees of biological complexity. Here, we consider GxExT interactions to understand adversity-induced developmental acceleration or deceleration whereby environmental conditions hasten or hinder children's development. To date, developmental pace changes have been largely explained through a focus on the individual: for example, how adversity "wears down" aging biological systems or how adversity accelerates or decelerates maturation to optimize reproductive fitness. We broaden such theories by positing shifts in developmental pace in response to the parent-child dyad's capacity or incapacity for meeting children's early, physiological and safety needs. We describe empirical evidence and potential neurobiological mechanisms supporting this new conceptualization of developmental acceleration and deceleration. We conclude with suggestions for future research on the developmental consequences of early adverse exposures.

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.

Placental DNA methylation marks are associated with maternal depressive symptoms during early pregnancy

Maternal depressive symptoms during pregnancy are a significant risk factor for adverse developmental and health outcomes of the offspring. The molecular mechanisms mediating the long-term effects of this exposure are not well understood. Previous studies have found association between prenatal exposure to maternal psychological distress and placental DNA methylation of candidate genes, which can influence placental barrier function and development of the fetus. Our objective in this study was to determine epigenome wide association of maternal depressive symptoms in early pregnancy with the placental DNA methylation. For this purpose we examined DNA methylomes of 92 placental samples by using reduced representation bisulfite sequencing. The placental samples were collected after deliveries of 39 girls and 59 boys, whose mothers had Edinburgh Postnatal Depression Score ranging from 0 to 19 at gestational week 14. According to our results maternal depressive symptoms are associated with DNA methylation of 2833 CpG sites, which are particularly over-represented in genic enhancers. The genes overlapping or nearest to these sites are functionally enriched for development of neurons and show expression enrichment in several regions of developing brain. The genomic regions harboring the DNA methylation marks are enriched for single nucleotide polymorphisms associated with mental disease trait class. Potential cellular signaling cascades mediating the effects include inflammatory and hormonal pathways. As a conclusion our results suggest that maternal depressive symptoms during early pregnancy are associated with DNA methylation marks in placenta in genes, which are important for the development and long-term health of the brain. Whether similar marks can be detected in exposed children remains to be elucidated in further studies.

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.

Exposure to Prenatal Stress Is Associated With an Excitatory/Inhibitory Imbalance in Rat Prefrontal Cortex and Amygdala and an Increased Risk for Emotional Dysregulation

Epidemiological studies have shown that environmental insults and maternal stress during pregnancy increase the risk of several psychiatric disorders in the offspring. Converging lines of evidence from humans, as well as from rodent models, suggest that prenatal stress (PNS) interferes with fetal development, ultimately determining changes in brain maturation and function that may lead to the onset of neuropsychiatric disorders. From a molecular standpoint, transcriptional alterations are thought to play a major role in this context and may contribute to the behavioral phenotype by shifting the expression of genes related to excitatory and inhibitory (E/I) transmission balance. Nevertheless, the exact neurophysiological mechanisms underlying the enhanced vulnerability to psychopathology following PNS exposure are not well understood. In the present study, we used a model of maternal stress in rats to investigate the distal effects of PNS on the expression of genes related to glutamatergic and GABAergic neurotransmissions. We inspected two critical brain regions involved in emotion regulation, namely, the prefrontal cortex (PFC) and the amygdala (AMY), which we show to relate with the mild behavioral effects detected in adult rat offspring. We observed that PNS exposure promotes E/I imbalance in the PFC of adult males only, by dysregulating the expression of glutamatergic-related genes. Moreover, such an effect is accompanied by increased expression of the activity-dependent synaptic modulator gene Npas4 specifically in the PFC parvalbumin (PV)-positive interneurons, suggesting an altered regulation of synapse formation promoting higher PV-dependent inhibitory transmission and increased overall circuit inhibition in the PFC of males. In the AMY, PNS more evidently affects the transcription of GABAergic-related genes, shifting the balance toward inhibition. Collectively, our findings suggest that the E/I dysregulation of the PFC-to-AMY transmission may be a long-term signature of PNS and may contribute to increase the risk for mood disorder upon further stress.

Prenatal origins of neuropsychiatric diseases

AIM

The main objective is to review the available evidence in the literature for developmental origins of neuropsychiatric diseases and their underlying mechanisms. We also probe emerging cutting-edge prenatal MR imaging tools and their future role in advancing our understanding the prenatal footprints of neuropsychiatric disorders.

OBSERVATIONS

Both human and animal studies support early intrauterine origins of neuropsychiatric disease, particularly autism spectrum disorders (ASD), attention and hyperactivity disorders, schizophrenia, depression, anxiety and mood disorders. Specific mechanisms of intrauterine injury include infection, inflammation, hypoxia, hypoperfusion, ischaemia polysubstance use/abuse, maternal mental health and placental dysfunction.

CONCLUSIONS AND RELEVANCE

There is ample evidence to suggest developmental vulnerability of the foetal brain to intrauterine exposures that increases and individual's risk for neuropsychiatric disease, especially the risk of ASD, depression and anxiety. Elucidating the exact timing and mechanisms of injury can be difficult and require novel, non-invasive approaches to the study emerging structural and functional brain development of the foetus. Clinical care should both emphasise maternal health during pregnancy, as well as close, continued monitoring for at risk offspring throughout young adulthood for the early identification and treatment of neuropsychiatric diseases.

Evolutionary Significance of the Neuroendocrine Stress Axis on Vertebrate Immunity and the Influence of the Microbiome on Early-Life Stress Regulation and Health Outcomes

Stress is broadly defined as the non-specific biological response to changes in homeostatic demands and is mediated by the evolutionarily conserved neuroendocrine networks of the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system. Activation of these networks results in transient release of glucocorticoids (cortisol) and catecholamines (epinephrine) into circulation, as well as activation of sympathetic fibers innervating end organs. These interventions thus regulate numerous physiological processes, including energy metabolism, cardiovascular physiology, and immunity, thereby adapting to cope with the perceived stressors. The developmental trajectory of the stress-axis is influenced by a number of factors, including the gut microbiome, which is the community of microbes that colonizes the gastrointestinal tract immediately following birth. The gut microbiome communicates with the brain through the production of metabolites and microbially derived signals, which are essential to human stress response network development. Ecological perturbations to the gut microbiome during early life may result in the alteration of signals implicated in developmental programming during this critical window, predisposing individuals to numerous diseases later in life. The vulnerability of stress response networks to maladaptive development has been exemplified through animal models determining a causal role for gut microbial ecosystems in HPA axis activity, stress reactivity, and brain development. In this review, we explore the evolutionary significance of the stress-axis system for health maintenance and review recent findings that connect early-life microbiome disturbances to alterations in the development of stress response networks.

Prenatal and postnatal depressive symptoms, infant white matter, and toddler behavioral problems

BACKGROUND

Maternal depression is prevalent during and following pregnancy and is related to adverse outcomes in offspring. Perinatal depression is associated with risk for difficulties in offspring; however, the mechanisms underlying this association are not clear. We examined whether maternal prenatal and postnatal depressive symptoms were associated with infant white matter organization and with behavioral problems in toddlerhood.

METHODS

37 mother-infant dyads (20 male; ages 5.95-7.66 months) participated in this study. We conducted diffusion MRI with infants during natural sleep. Mothers reported on their prenatal and postnatal depressive symptoms at six months postpartum. We calculated fractional anisotropy (FA), radial, axial, and mean diffusivity, and assessed offspring behavioral problems at age 18 months.

RESULTS

Prenatal depressive symptoms were associated with FA of the corpus callosum; postnatal depressive symptoms were not associated with FA of limbic tracts or corpus callosum segmentations. Higher levels of prenatal depressive symptoms were associated with higher FA and lower radial diffusivity of the corpus callosum genu; FA of this region was positively associated with behavioral problems at age 18 months.

LIMITATIONS

This study had a small sample size; therefore, findings should be replicated. Further, we used retrospective reports of maternal prenatal depression, but validated them in this study.

CONCLUSIONS

Depressive symptoms during pregnancy may affect infant corpus callosum development and, in turn, offspring behaviors. These findings suggest that early maternal stress accelerates infant neurodevelopment in a manner that may increase risk for behavioral problems. Thus, efforts to reduce maternal prenatal depression should be a public health priority.