Predictions of children's emotionality from evolutionary and epigenetic hypotheses

Epigenetics of prenatal stress in humans: the current research landscape

Fetal exposure to prenatal stress can have significant consequences on short- and long-term health. Epigenetic mechanisms, especially DNA methylation (DNAm), are a possible process how these adverse environmental events could be biologically embedded. We evaluated candidate gene as well as epigenome-wide association studies associating prenatal stress and DNAm changes in peripheral tissues; however, most of these findings lack robust replication. Prenatal stress-associated epigenetic changes have also been linked to child health including internalizing problems, neurobehavioral outcomes and stress reactivity. Future studies should focus on refined measurement and definition of prenatal stress and its timing, ideally also incorporating genomic as well as longitudinal information. This will provide further opportunities to enhance our understanding of the biological embedding of prenatal stress exposure.

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).

An examination of behavioural and emotional problems in children exposed prenatally to the 27F Chilean earthquake: findings from the ELPI cohort

PURPOSE

Associations between prenatal earthquake exposure and children's mental health remain unclear. Moreover, there is a paucity of research using quasi-experimental statistical techniques to diminish potential selection bias. Thus, this study aimed to explore the impact of prenatal exposure to the Chilean earthquake of 2010 on children's behavioural and emotional problems between 1½ and 3 years old using propensity score matching.

METHODS

Participants included 1549 families from the Encuesta Longitudinal de la Primera Infancia cohort in Chile. Maternal reports using the Child Behaviour Checklist (CBCL) were used to assess behavioural and emotional problems between 1½ and 3 years old. Information on prenatal earthquake exposure was collected via maternal report. The Kernel matching estimator was used to compare the average treatment effects of children who were exposed to the earthquake compared to those who were not.

RESULTS

Five of the seven CBCL outcomes were statistically significant after matching and adjustment for multiple testing, suggesting greater difficulties for exposed children which included emotional reactivity, anxious/depressed, sleep problems, attention problems, and aggression (mean difference of 0.69, 0.87, 0.73, 0.85, 3.51, respectively). The magnitude of the effect was small to medium.

CONCLUSION

Findings contribute to the potential causal inferences between prenatal earthquake exposure and increased behavioural and emotional problems in early childhood. Results suggest that in utero experiences may have long-term consequences for infants' well-being, supporting the need for specific interventions in pregnancy after natural disasters.

Maternal and paternal depression and child mental health trajectories: evidence from the Avon Longitudinal Study of Parents and Children

BACKGROUND

The relationships between offspring depression profiles across adolescence and different timings of parental depression during the perinatal period remain unknown.

AIMS

To explore different timings of maternal and paternal perinatal depression in relation to patterns of change in offspring depressive mood over a 14 year period.

METHOD

Data were obtained from the Avon Longitudinal Study of Parents and Children (ALSPAC). Parental antenatal depression (ANTD) was assessed at 18 weeks gestation, and postnatal depression (PNTD) at 8 weeks postpartum. Population-averaged trajectories of offspring depressive symptoms were estimated using the Short Mood and Feelings Questionnaire (SMFQ) on nine occasions between 10 and 24 years of age.

RESULTS

Full data were available for 5029 individuals. Offspring exposed to both timings of maternal depression had higher depressive symptoms across adolescence compared with offspring not exposed to ANTD or PNTD, characterised by higher depressive symptoms at age 16 (7.07 SMFQ points (95% CI = 6.19, 7.95; P < 0.001)) and a greater rate of linear change (0.698 SMFQ points (95% CI = 0.47, 0.93; P = 0.002)). Isolated maternal ANTD and to a lesser extent PNTD were also both associated with higher depressive symptoms at age 16, yet isolated maternal PNTD showed greater evidence for an increased rate of linear change across adolescence. A similar pattern was observed for paternal ANTD and PNTD, although effect sizes were attenuated.

CONCLUSIONS

This study adds to the literature demonstrating that exposure to two timings of maternal depression (ANTD and PNTD) is strongly associated with greater offspring trajectories of depressive symptoms.

Prenatal programming of depression: cumulative risk or mismatch in the Ontario Child Health Study?

Consistent with cumulative risk hypotheses of psychopathology, studies examining prenatal adversity and later mental health largely suggest that pre and postnatal stress exposures have summative effects. Fewer data support that a mismatch in stress levels between pre- and postnatal life increases risk (the mismatch hypothesis). In this retrospective cohort study using data from the 1983 Ontario Child Health Study (OCHS), we examined interactions between birth weight status and childhood/adolescent stress to predict major depression in adulthood. Ninety-five participants born at low birth weight (LBW; <2500 g) and 972 normal birth weight (NBW) control participants completed the Composite International Diagnostic Interview Short-Form Major Depression module at 21-34 years of age. A youth risk scale consisting of five stressful exposures (family dysfunction, socioeconomic disadvantage, parental criminality, maternal mental illness, exposure to other life stresses) indexed child/adolescent adversity. Birth weight groups did not differ by childhood risk score nor depression levels. A significant interaction was observed between birth weight and the youth risk scale whereby exposure to increasing levels of exposure to childhood/adolescent adversity predicted increased levels of depression in the NBW group, but lower rates in those born at LBW. Consistent with the mismatch hypothesis, data from a large, longitudinally followed cohort suggest that the mental health of adults born LBW may be more resilient to the adverse effects of childhood/adolescent stress. Taken in the context of previous studies of low birth weight infants, these findings suggest that the nature of associations between gestational stress and later mental health may depend on the magnitude of prenatal stress exposure, as well as the degree of resilience and/or plasticity conferred by their early-life environment.

Sex differences in foetal origins of child emotional symptoms: a test of evolutionary hypotheses in a large, general population cohort

BACKGROUND

Based on previous findings from the Wirral Child Health and Development Study (WCHADS), and on evolutionary hypotheses, we preregistered analyses of data from a large epidemiological sample (https://osf.io/fn5g9/register/564d31db8c5e4a7c9694b2be), to test for sex-dependent moderation by prenatal maternal depressive symptoms of the association between postnatal maternal depressive symptoms and child emotional problems.

METHODS

A total of 8,354 mothers and children were followed from pregnancy to 3.5 years in the Avon Longitudinal Study of Parents and Children (ALSPAC). Self-report measures of prenatal and postnatal maternal depressive symptoms, and maternal report of child emotional symptoms were administered.

RESULTS

There was a three-way interaction between maternal prenatal and postnatal depression, and child sex (Coeff .042 95% CI 0.015 to 0.068, p = .002). This arose from moderation by prenatal depression, in opposite directions in boys and in girls. In boys, the association between postnatal depression and child emotional symptoms was weaker following lower prenatal depressive symptoms (interaction term coeff = .030, p = .001), and in girls, to a lesser extent, the association was stronger following lower prenatal depressive symptoms (interaction term coeff = -.012, p = .221).

CONCLUSIONS

We replicated the finding from the WCHADS that prenatal depression modifies the association between postnatal depression and children's emotional problems in a sex-dependent fashion. In ALSPAC, the sex difference was explained mainly by a protective effect of low prenatal depression in boys, while in WCHADS, it arose from greater vulnerability of girls to postnatal depression following low prenatal depression. In the light of these findings, in evaluating and implementing early interventions, there is need to consider that risks associated with postnatal depression may vary depending on maternal mood during pregnancy and may differ between boys and girls.

Epigenetic Mechanisms in the Neurodevelopmental Theory of Depression

The genome (genes), epigenome, and environment work together from the earliest stages of human life to produce a phenotype of human health or disease. Epigenetic modifications, including among other things: DNA methylation, modifications of histones and chromatin structure, as well as functions of noncoding RNA, are coresponsible for specific patterns of gene expression. This refers also to mental disorders, including depressive disorders. Early childhood experiences accompanied by severe stressors (considered a risk factor for depression in adult life) are linked with changes in gene expression. They include genes involved in a response to stress (hypothalamic-pituitary-adrenal axis, HPA), associated with autonomic nervous system hyperactivity and with cortical, and subcortical processes of neuroplasticity and neurodegeneration. These are, among others: gene encoding glucocorticoid receptor, FK506 binding protein 5 gene (FKBP5), gene encoding arginine vasopressin and oestrogen receptor alpha, 5-hydroxy-tryptamine transporter gene (SLC6A4), and gene encoding brain-derived neurotrophic factor. How about personality? Can the experiences unique to every human being, the history of his or her development and gene-environment interactions, through epigenetic mechanisms, shape the features of our personality? Can we pass on these features to future generations? Hence, is the risk of depression inherent in our biological nature? Can we change our destiny?

Mismatched Prenatal and Postnatal Maternal Depressive Symptoms and Child Behaviours: A Sex-Dependent Role for NR3C1 DNA Methylation in the Wirral Child Health and Development Study

Evolutionary hypotheses predict that male fetuses are more vulnerable to poor maternal conditions (Sex-biased Maternal Investment), but female fetuses are at greater risk of glucocorticoid-mediated disorders where there is a mismatch between fetal and postnatal environments (Predictive Adaptive Response). Self-reported prenatal and postnatal depression and maternal report of child anxious-depressed symptoms at 2.5, 3.5 and 5.0 years were obtained from an ‘extensive’ sample of first-time mothers (N = 794). Salivary NR3C1 1-F promoter methylation was assayed at 14 months in an ‘intensive’ subsample (n = 176) and stratified by psychosocial risk. Generalised structural equation models were fitted and estimated by maximum likelihood to allow the inclusion of participants from both intensive and extensive samples. Postnatal depression was associated with NR3C1 methylation and anxious-depressed symptoms in daughters of mothers with low prenatal depression (prenatal-postnatal depression interaction for methylation, p < 0.001; for child symptoms, p = 0.011). In girls, NR3C1 methylation mediated the association between maternal depression and child anxious-depressed symptoms. The effects were greater in girls than boys: the test of sex differences in the effect of the prenatal-postnatal depression interaction on both outcomes gave X² (2) = 5.95 (p = 0.051). This was the first human study to show that epigenetic and early behavioural outcomes may arise through different mechanisms in males and females.