Sensitive Periods for the Effect of Childhood Adversity on DNA Methylation: Results From a Prospective, Longitudinal Study

Early-life adversity severity, timing, and context type are associated with SLC6A4 methylation in emerging adults: Results from a prospective cohort study

BACKGROUND

Epigenetic modifications, including DNA methylation (DNAm), can play a role in the biological embedding of early-life adversity (ELA) through serotonergic mechanisms. The current study examines methylation of the CpG island in the promoter region of the stress-responsive serotonin transporter gene (SLC6A4) and is the first to jointly assess how it is influenced by ELA severity, timing, and type-specifically, deprivation and threat.

METHODS

We use data from 627 Youth Emotion Project study participants, recruited from two US high schools. Using adjusted linear regressions, we analyze DNA collected in early adulthood from 410 participants and ELA based on interviewer-rated responses from concurrent Childhood Trauma Interviews, adjusting for survey-measured covariates.

RESULTS

ELA robustly predicted mean CpG island SLC6A4 DNAm percent across 71 CpG sites. Each additional major-severity ELA event was associated with a 0.121-percentage-point increase (p<0.001), equating to a 0.177 standard deviation (sd) higher DNAm level (95 % CI: 0.080, 0.274) with each 1-sd higher adversity score. When modeled separately, both childhood and adolescent ELA predicted SLC6A4 DNAm. When modeled jointly, adolescent ELA was most strongly predictive, and child adversity remained significantly associated with DNAm through indirect associations via adolescent adversity. Additionally, the ELA-SLC6A4 DNAm association may vary by adversity type. Across separate models for childhood and adolescent exposures, deprivation coefficients are positive and statistically significant. Meanwhile, threat coefficients are positive and not significantly significant but do not statistically differ from deprivation coefficients. In models including all ELA dimensions, one major adolescent deprivation event is associated with a 0.222-percentage-point increased SLC6A4 DNAm (p<0.05), or a 1-sd higher deprivation score with a 0.157-sd increased DNAm.

CONCLUSION

Results further implicate epigenetic modification on serotonergic neurotransmission via DNAm in the downstream sequelae of ELA-particularly adolescent deprivation-and support preventive interventions in adolescence to mitigate biological embedding.

PRKCB methylation: a potential biomarker of MDD with childhood chronic stress, a cross-sectional study in drug-naive, first-episode adolescent MDD

The purpose of this study was to investigate the relationship between childhood chronic stress(CCS), Protein kinase C beta (PRKCB) methylation and adolescent major depressive disorder (MDD). After recruiting 100 adolescents with MDD and 50 healthy controls (HCs), we evaluated the severity of CCS. PRKCB methylation was assessed by pyrosequencing using whole blood-derived DNA. To explore the relationship between CCS, PRKCB and adolescent MDD, we conducted correlation analysis and regression analysis, and constructed multiplicative interaction models and generalized linear models. PRKCB methylation and CCS were both found to be associated with MDD, and CCS was associated with PRKCB methylation. No significant CCS-PRKCB methylation interactions were observed. However, we found the interaction of CCS and MDD on PRKCB methylation. Our results found that PRKCB methylation was influenced by CCS and the disease itself, and PRKCB methylation was significantly positively associated with MDD severity, suggesting that PRKCB methylation may be a potential biomarker for adolescent MDD. This study is a cross-sectional observational study, which cannot draw the conclusion of causality. Prospective cohort studies are needed to further examine the relationship between CCS, adolescent MDD, and PRKCB methylation.

Developmental Timing of Associations Among Parenting, Brain Architecture, and Mental Health

Importance

Parenting is associated with brain development and long-term health outcomes, although whether these associations depend on the developmental timing of exposure remains understudied. Identifying these sensitive periods can inform when and how parenting is associated with neurodevelopment and risk for mental illness.

Objective

To characterize how harsh and warm parenting during early, middle, and late childhood are associated with brain architecture during adolescence and, in turn, psychiatric symptoms in early adulthood during the COVID-19 pandemic.

Design, Setting, and Participants

This population-based, 21-year observational, longitudinal birth cohort study of low-income youths and families from Detroit, Michigan; Toledo, Ohio; and Chicago, Illinois, used data from the Future of Families and Child Well-being Study. Data were collected from February 1998 to June 2021. Analyses were conducted from May to October 2023.

Exposures

Parent-reported harsh parenting (psychological aggression or physical aggression) and observer-rated warm parenting (responsiveness) at ages 3, 5, and 9 years.

Main Outcomes and Measures

The primary outcomes were brainwide (segregation, integration, and small-worldness), circuit (prefrontal cortex [PFC]-amygdala connectivity), and regional (betweenness centrality of amygdala and PFC) architecture at age 15 years, determined using functional magnetic resonance imaging, and youth-reported anxiety and depression symptoms at age 21 years. The structured life-course modeling approach was used to disentangle timing-dependent from cumulative associations between parenting and brain architecture.

Results

A total of 173 youths (mean [SD] age, 15.88 [0.53] years; 95 female [55%]) were included. Parental psychological aggression during early childhood was positively associated with brainwide segregation (β = 0.30; 95% CI, 0.14 to 0.45) and small-worldness (β = 0.17; 95% CI, 0.03 to 0.28), whereas parental psychological aggression during late childhood was negatively associated with PFC-amygdala connectivity (β = -0.37; 95% CI, -0.55 to -0.12). Warm parenting during middle childhood was positively associated with amygdala centrality (β = 0.23; 95% CI, 0.06 to 0.38) and negatively associated with PFC centrality (β = -0.18; 95% CI, -0.31 to -0.03). Warmer parenting during middle childhood was associated with reduced anxiety (β = -0.05; 95% CI -0.10 to -0.01) and depression (β = -0.05; 95% CI -0.10 to -0.003) during early adulthood via greater adolescent amygdala centrality.

Conclusions and Relevance

Neural associations with harsh parenting were widespread across the brain in early childhood but localized in late childhood. Neural associations with warm parenting were localized in middle childhood and, in turn, were associated with mental health during future stress. These developmentally contingent associations can inform the type and timing of interventions.

Childhood adversity and adolescent mental health: Examining cumulative and specificity effects across contexts and developmental timing

Associations between adversity and youth psychopathology likely vary based on the types and timing of experiences. Major theories suggest that the impact of childhood adversity may either be cumulative in type (the more types of adversity, the worse outcomes) or in timing (the longer exposure, the worse outcomes) or, alternatively, specific concerning the type (e.g., parenting, home, neighborhood) or the timing of adversity (e.g., specific developmental periods). In a longitudinal sample from the Future of Families and Wellbeing Study (N = 4,210), we evaluated these competing hypotheses using a data-driven structured life-course modeling approach using risk factors examined at child age 1 (infancy), 3 (toddlerhood), 5 (early childhood), and 9 (middle childhood). Results showed that exposures to more types of adversity for longer durations (i.e., cumulative in both type and timing) best predicted youth psychopathology. Adversities that occurred at age 9 were better predictors of youth psychopathology as compared to those experienced earlier, except for neglect, which was predictive of internalizing symptoms when experienced at age 3. Throughout childhood (across ages 1-9), aside from the accumulation of all adversities, parental stress and low collective efficacy were the strongest predictors of internalizing symptoms, whereas psychological aggression was predictive of externalizing symptoms.

The relationship between type, timing and duration of exposure to adverse childhood experiences and adolescent self-harm and depression: findings from three UK prospective population-based cohorts

BACKGROUND

Adverse childhood experiences (ACEs) are well-established risk factors for self-harm and depression. However, despite their high comorbidity, there has been little focus on the impact of developmental timing and the duration of exposure to ACEs on co-occurring self-harm and depression.

METHODS

Data were utilised from over 22,000 children and adolescents participating in three UK cohorts, followed up longitudinally for 14-18 years: the Avon Longitudinal Study of Parents and Children (ALSPAC), the Millennium Cohort Study (MCS) and the Environmental Risk (E-Risk) Longitudinal Twin Study. Multinomial logistic regression models estimated associations between each ACE type and a four-category outcome: no self-harm or depression, self-harm alone, depression alone and self-harm with co-occurring depression. A structured life course modelling approach was used to examine whether the accumulation (duration) of exposure to each ACE, or a critical period (timing of ACEs) had the strongest effects on self-harm and depression in adolescence.

RESULTS

The majority of ACEs were associated with co-occurring self-harm and depression, with consistent findings across cohorts. The importance of timing and duration of ACEs differed across ACEs and across cohorts. For parental mental health problems, longer duration of exposure was strongly associated with co-occurring self-harm and depression in both ALSPAC (adjusted OR: 1.18, 95% CI: 1.10-1.25) and MCS (1.18, 1.11-1.26) cohorts. For other ACEs in ALSPAC, exposure in middle childhood was most strongly associated with co-occurring self-harm and depression, and ACE occurrence in early childhood and adolescence was more important in the MCS.

CONCLUSIONS

Efforts to mitigate the impact of ACEs should start in early life with continued support throughout childhood, to prevent long-term exposure to ACEs contributing to risk of self-harm and depression in adolescence.

DNA methylation signatures of prenatal socioeconomic position associated with 36-month language outcomes

BACKGROUND

Socioeconomic position (SEP), which reflects one's position in society and access to resources, is strongly tied to neurodevelopment and is associated with epigenetic changes.

AIM

This study examined whether DNA methylation signatures of prenatal SEP, measured in birth samples, are associated with child neurodevelopmental outcomes at 36 months of age.

METHODS

Prenatal SEP DNA methylation scores were derived using 97 placenta and 127 cord blood biospecimens in the Early Autism Risk Longitudinal Investigation cohort. Participants completed the Mullen Scales of Early Learning (MSEL) and Vineland Adaptive Behavior Scales (VABS) at 36 months of age. Generalized regression analyses, adjusting for maternal age and race, were performed to test the association between SEP methylation score, for each birth biospecimen type, and MSEL and VABS scores.

RESULTS

Significant associations were observed between placenta SEP methylation score and MSEL Expressive Language outcomes (beta = -2.7, p = 0.046, 95 % CI [- 5.43, -0.05]) and Receptive Language outcomes (beta = -2.5, p = 0.037, 95 % CI [-4.82, -0.16]). In cord blood, methylation-SEP scores were significantly associated with Receptive Language outcomes (beta = -2.0, p = 0.037, 95 % CI [-3.85, -0.12]). No significant associations were observed with VABS scores.

CONCLUSION

Our results confirm associations between prenatal SEP and early childhood language development using a novel empiric DNA methylation measure of exposure.

Revisiting adolescence as a sensitive period for sociocultural processing

Waves of research and public discourse have characterized adolescence as periods of developmental risk and opportunity. Underlying this discussion is the recognition that adolescence is a period of major biological and social transition when experience may have an outsized effect on development. This article updates and expands upon prior work suggesting that adolescence may be a sensitive period for sociocultural processing specifically. By integrating evidence from developmental psychology and neuroscience, we identify how trajectories of social and neurobiological development may relate to adolescents' ability to adapt to and learn from their social environments. However, we also highlight gaps in the literature, including challenges in attributing developmental change to adolescent experiences. We discuss the importance of better understanding variability in biology (e.g., pubertal development) and cultural environments, as well as distinguishing between sensitive periods and periods of heightened sensitivity. Finally, we look toward future directions and translational implications of this research.

Longitudinal DNA methylation in parent-infant pairs impacted by intergenerational social adversity: An RCT of the Michigan Model of Infant Mental Health Home Visiting

INTRODUCTION

Early childhood development is a strong predictor of long-term health outcomes, potentially mediated via epigenetics (DNA methylation). The aim of the current study was to examine how childhood experiences, punitive parenting, and an intergenerational psychotherapeutic intervention may impact DNA methylation in young children and their mothers.

METHODS

Mothers and their infants/toddlers between 0 and 24 months were recruited at baseline (n = 146, 73 pairs) to participate in a randomized control trial evaluating the effectiveness of The Michigan Model of Infant Mental Health Home Visiting (IMH-HV) parent-infant psychotherapy compared to treatment as usual. Baseline and 12-month post-enrollment data were collected in the family's home and included self-report questionnaires, biological saliva samples, home environment observation, video-taped parent-child interaction, and audio-recorded interviews. Saliva DNA methylation was measured at the genes, nuclear receptor subfamily 3 group C member 1 (NR3C1), solute carrier family 6 member 4 (SLC6A4), brain-derived neurotrophic factor (BDNF), and the genetic element, long interspersed nuclear element-1 (LINE1).

RESULTS

For mothers, baseline methylation of BDNF, SLC6A4, NR3C1, or LINE1 was largely not associated with baseline measures of their childhood adversity, adverse life experiences, demographic characteristics related to structurally driven inequities, or to IMH-HV treatment effect. In infants, there were suggestions that methylation in SLC6A4 and LINE1 was associated with parenting attitudes. Infant BDNF methylation suggested an overall decrease in response to IMH-HV psychotherapy over 12 months.

CONCLUSIONS

Overall, our findings suggest that the epigenome in infants and young children may be sensitive to both early life experiences and parent-infant psychotherapy.

Reading children's teeth to reconstruct life history and the evolution of human cooperation and cognition: The role of dental enamel microstructure and chemistry

Studying infants in the past is crucial for understanding the evolution of human life history and the evolution of cooperation, cognition, and communication. An infant's growth, health, and mortality can provide information about the dynamics and structure of a population, their cultural practices, and the adaptive capacity of a community. Skeletal remains provide one way of accessing this information for humans recovered prior to the historical periods. Teeth in particular, are retrospective archives of information that can be accessed through morphological, micromorphological, and biogeochemical methods. This review discusses how the microanatomy and formation of teeth, and particularly enamel, serve as archives of somatic growth, stress, and the environment. Examining their role in the broader context of human evolution, we discuss dental biogeochemistry and emphasize how the incremental growth of tooth microstructure facilitates the reconstruction of temporal data related to health, diet, mobility, and stress in past societies. The review concludes by considering tooth microstructure as a biomarker and the potential clinical applications.

Associations of altered leukocyte DDR1 promoter methylation and childhood trauma with bipolar disorder and suicidal behavior in euthymic patients

Altered DNA methylation (DNAm) patterns of discoidin domain receptor 1 (DDR1) have been found in the blood and brain of patients with schizophrenia (SCZ) and the brain of patients with bipolar disorder (BD). Childhood trauma (CT) is associated with changes in DNAm that in turn are related to suicidal behavior (SB) in patients with several psychiatric disorders. Here, using MassARRAY® technology, we studied 128 patients diagnosed with BD in remission and 141 healthy controls (HCs) to compare leukocyte DDR1 promoter DNAm patterns between patients and HCs and between patients with and without SB. Additionally, we investigated whether CT was associated with DDR1 DNAm and mediated SB. We found hypermethylation at DDR1 cg19215110 and cg23953820 sites and hypomethylation at cg14279856 and cg03270204 sites in patients with BD compared to HCs. Logistic regression models showed that hypermethylation of DDR1 cg23953820 but not cg19215110 and CT were risk factors for BD, while cg14279856 and cg03270204 hypomethylation were protective factors. In patients, CT was a risk factor for SB, but DDR1 DNAm, although associated with CT, did not mediate the association of CT with SB. This is the first study demonstrating altered leukocyte DDR1 promoter DNAm in euthymic patients with BD. We conclude that altered DDR1 DNAm may be related to immune and inflammatory mechanisms and could be a potential blood biomarker for the diagnosis and stratification of psychiatric patients.

Validation of the Chinese version of the adverse life experiences scale

Background

Adverse childhood experiences (ACEs) are strongly linked to many mental health problems, and play important role in the intergenerational transmission of psychopathology. Additionally, the developmental timing may also be critical in ACEs' impact on these problems. The Adverse Life Experiences Scale (ALES), as a recently developed measure, has demonstrated good reliability and validity in indexing cumulative risk, developmental timing, and intergenerational transmission. This scale has not been used in China. The purpose of present study was to revise the Chinese version of the ALES and examine its psychometric properties.

Methods

A total of 527 parents (fathers n = 246, mothers n = 281) from families with at least one child (12-18 years) completed this online survey. Internal consistency, test-retest reliability, correlations, regression models were examined for assessing the psychometric properties of the Chinese version of the ALES.

Results

The Chinese version of the ALES showed acceptable internal consistency (children: α = .72, parents: α = .74) and test-retest reliability (children: r = .86, parents: r = .84). In terms of validity, both parents and children's ACEs scores (total score and most age intervals scores) were significantly correlated with their current symptoms; ACEs scores of some age intervals in early childhood and adolescence significantly predicted symptoms in regression models; and parents' ACEs total score significantly correlated with children's ACEs total score and symptoms (all, girls, boys) except boys' Strengths and Difficulties Questionnaire total score.

Conclusion

The Chinese version of the ALES showed good psychometric properties for assessing ACEs cumulative risk, developmental timing, and intergenerational transmission, and can serve as a reliable tool to evaluate ACEs in Chinese samples.

Telehealth Parenting Program and Salivary Epigenetic Biomarkers in Preschool Children With Developmental Delay: NIMHD Social Epigenomics Program

Importance

Children with developmental delays are at a heightened risk of experiencing mental health challenges, and this risk is exacerbated among racially minoritized children who face disproportionate adversity. Understanding the impact of parenting interventions on biological markers associated with these risks is crucial for mitigating long-term health disparities.

Objective

To examine the effect of 20 weeks of an internet-based parent-child interaction training (iPCIT) program on biomarkers associated with aging and chronic inflammation among preschoolers with developmental delay at 12-month follow-up.

Design, Setting, and Participants

An observational secondary analysis of data from a randomized clinical trial conducted from March 17, 2016, to December 15, 2020, to assess changes in salivary DNA methylation (DNAm)-derived biomarkers following iPCIT intervention. Participants were recruited from 3 Part C early intervention sites in a large southeastern US city. Eligible participants included children recruited within 3 months of their third birthday who had a Child Behavior Checklist Externalizing Problems T score greater than 60 and provided saliva in at least 1 study wave. Data analysis was conducted May 2023 to April 2024.

Intervention

Participants received either iPCIT (a telehealth therapeutic intervention focused on enhancing the parent-child relationship and addressing behavioral challenges in young children) or referrals as usual.

Main Outcomes and Measures

DNAm at the 12-month follow-up was assessed using the Infinium HumanMethylationEPIC Bead Chip Assay to derive biomarkers DunedinPACE, C-reactive protein (CRP), and interleukin-6 (IL-6). Analyses were intent-to-treat and used path analysis.

Results

A total of 71 children (mean [SD] age, 36.27 [0.61] months 51 male [71.8%] and 20 female [28.2%]) were analyzed, of whom 34 received iPCIT and 37 received referrals as usual. The iPCIT group had a slower pace of aging (β = 0.26; 95% CI, 0.06 to 0.50; P = .03) and less DNAm-derived CRP (β = 0.27; 95% CI, 0.05 to 0.49; P = .01) relative to the control condition at the 12-month follow-up. These associations remained significant after accounting for baseline DNAm score, child demographics, and symptom severity, and were independent of predicted buccal epithelial cell proportion for both DunedinPACE and CRP. There was no association with DNAm-derived IL-6 (β = 0.14; 95% CI, -0.08 to 0.36; P = .21).

Conclusions and Relevance

In this study of a parenting intervention, iPCIT, the association of intervention with decreased molecular markers of inflammation and biological aging suggests their potential to modify aspects of the biological embedding of stress. Understanding the systemic biological impact of such interventions offers insights into addressing health disparities and promoting resilience among vulnerable populations.

Trial Registration

ClinicalTrials.gov Identifier: NCT03260816.

Elevated risk for psychiatric outcomes in pediatric patients with Multisystem Inflammatory Syndrome (MIS-C): A review of neuroinflammatory and psychosocial stressors

Multisystem Inflammatory Syndrome in Children (MIS-C) is a secondary immune manifestation of COVID-19 involving multiple organ systems in the body, resulting in fever, skin rash, abdominal pain, nausea, shock, and cardiac dysfunction that often lead to hospitalization. Although many of these symptoms resolve following anti-inflammatory treatment, the long-term neurological and psychiatric sequelae of MIS-C are unknown. In this review, we will summarize two domains of the MIS-C disease course, 1) Neuroinflammation in the MIS-C brain and 2) Psychosocial disruptions resulting from stress and hospitalization. In both domains, we present existing clinical findings and hypothesize potential connections to psychiatric outcomes. This is the first review to conceptualize a holistic framework of psychiatric risk in MIS-C patients that includes neuroinflammatory and psychosocial risk factors. As cases of severe COVID-19 and MIS-C subside, it is important for clinicians to monitor outcomes in this vulnerable patient population.

Childhood Maltreatment and Longitudinal Epigenetic Aging: NIMHD Social Epigenomics Program

Importance

Child physical and emotional abuse and neglect may affect epigenetic signatures of accelerated aging several years after the exposure.

Objective

To examine the longitudinal outcomes of early-childhood and midchildhood exposures to maltreatment on later childhood and adolescent profiles of epigenetic accelerated aging.

Design, Setting, and Participants

This cohort study used data from the Future of Families and Child Wellbeing Study (enrolled 1998-2000), a US birth cohort study with available DNA methylation (DNAm) data at ages 9 and 15 years (assayed between 2017 and 2020) and phenotypic data at birth (wave 1), and ages 3 (wave 3), 5 (wave 4), 9 (wave 5), and 15 (wave 6) years. Data were analyzed between June 18 and December 10, 2023.

Exposures

Emotional aggression, physical assault, emotional neglect, and physical neglect via the Parent-Child Conflict Tactics Scale at ages 3 and 5 years.

Main Outcomes and Measures

Epigenetic accelerated aging (DNAmAA) was measured using 3 machine learning-derived surrogates of aging (GrimAge, PhenoAge, and DunedinPACE) and 2 machine learning-derived surrogates of age (Horvath and PedBE), residualized for age in months.

Results

A total of 1971 children (992 [50.3%] male) representative of births in large US cities between 1998 and 2000 were included. Physical assault at age 3 years was positively associated with DNAmAA for PhenoAge (β = 0.073; 95% CI, 0.019-0.127), and emotional aggression at age 3 years was negatively associated with PhenoAge DNAmAA (β = -0.107; 95% CI, -0.162 to -0.052). Emotional neglect at age 5 years was positively associated with PhenoAge DNAmAA (β = 0.051; 95% CI, 0.006-0.097). Cumulative exposure to physical assault between ages 3 and 5 years was positively associated with PhenoAge DNAmAA (β = 0.063; 95% CI, 0.003-0.123); emotional aggression was negatively associated with PhenoAge DNAmAA (β = -0.104; 95% CI, -0.165 to -0.043). The association of these measures with age 15 years PhenoAge DNAmAA was almost fully mediated by age 9 years PhenoAge DNAm age acceleration. Similar patterns were found for GrimAge, DunedinPACE, and PhenoAge, but only those for PhenoAge remained after adjustments for multiple comparisons.

Conclusions and Relevance

In this cohort study, altered patterns of DNAmAA were sensitive to the type and timing of child maltreatment exposure and appeared to be associated with more proximate biological embedding of stress.

Black and Latiné parents' perspectives on supporting their children's emotional and physical health

Informed by integrative models of cultural resilience, the purpose of this study was to (a) explore how parents are promoting their children's emotional and physical health, with a focus on race and ethnic-racial socialization strategies, and (b) identify the barriers and challenges parents are experiencing in supporting their children's health. Ethnically racially matched qualitative interviews were conducted with 33 parents (82% women, 64% Black, 36% Latiné). Results of thematic analysis revealed three overarching themes: (a) Strategies for Promoting Children's Physical and Emotional Health, (b) Challenges Promoting Children's Physical and Emotional Health, and (c) Impact of Racism on Parenting and Children's Health. Most parents believed that racism had an impact on their parenting decisions and their children's health; however, there were some differences in ethnic-racial socialization practices between Black and Latiné parents. Findings have implications for culturally relevant parenting approaches to support children's emotional and physical health.

Towards a Novel Frontier in the Use of Epigenetic Clocks in Epidemiology

Health problems associated with aging are a major public health concern for the future. Aging is a complex process with wide intervariability among individuals. Therefore, there is a need for innovative public health strategies that target factors associated with aging and the development of tools to assess the effectiveness of these strategies accurately. Novel approaches to measure biological age, such as epigenetic clocks, have become relevant. These clocks use non-sequential variable information from the genome and employ mathematical algorithms to estimate biological age based on DNA methylation levels. Therefore, in the present study, we comprehensively review the current status of the epigenetic clocks and their associations across the human phenome. We emphasize the potential utility of these tools in an epidemiological context, particularly in evaluating the impact of public health interventions focused on promoting healthy aging. Our review describes associations between epigenetic clocks and multiple traits across the life and health span. Additionally, we highlighted the evolution of studies beyond mere associations to establish causal mechanisms between epigenetic age and disease. We explored the application of epigenetic clocks to measure the efficacy of interventions focusing on rejuvenation.

The biological embedding of social adversity: How adolescent housing insecurity impacts inflammation over time

BACKGROUND & PURPOSE

Adolescent housing insecurity is a dynamic form of social adversity that impacts child health outcomes worldwide. However, the means by which adolescent housing insecurity may become biologically embedded to influence health outcomes over the life course remain unclear. Therefore, we aimed to utilize life course perspectives and advanced causal inference methods to evaluate the potential for inflammation to contribute to the biological embedding of adolescent housing insecurity.

MATERIALS AND METHODS

Using prospective data from the Great Smoky Mountains Study, we investigated the relationship between adolescent housing insecurity and whole-blood spot samples assayed for C-reactive protein (CRP). Adolescent housing insecurity was created based on annual measures of frequent residential moves, reduced standard of living, forced separation from the home, and foster care. Annual measures of CRP ranged from 0.001 mg/L to 13.6 mg/L (median = 0.427 mg/L) and were log10 transformed to account for positively skewed values. We used g-estimation of structural nested mean models to estimate a series of conditional average causal effects of adolescent housing insecurity on CRP levels from ages 11 to 16 years and interpreted the results within life course frameworks of accumulation, recency, and sensitive periods.

PRINCIPAL RESULTS

Of the 1,334 participants, 427 [44.3 %] were female. Based on the conditional average causal effect, one exposure to adolescent housing insecurity from ages 11 to 16 years led to a 6.4 % (95 % CI = 0.69 - 12.4) increase in later CRP levels. Exposure at 14 years of age led to a 27.9 % increase in CRP levels at age 15 (95 % CI = 6.5 - 53.5). Recent exposures to adolescent housing insecurity (<3 years) suggested stronger associations with CRP levels than distant exposures (>3 years), but limited statistical power prevented causal conclusions regarding recency effects at the risk of a Type II Error.

MAJOR CONCLUSIONS

These findings highlight inflammation-as indicated by increased CRP levels-as one potential mechanism for the biological embedding of adolescent housing insecurity. The results also suggest that adolescent housing insecurity-particularly recent, repeated, and mid-adolescent exposures-may increase the risk of poor health outcomes and should be considered a key intervention target.

Individual longitudinal changes in DNA-methylome identify signatures of early-life adversity and correlate with later outcome

Adverse early-life experiences (ELA) affect a majority of the world's children. Whereas the enduring impact of ELA on cognitive and emotional health is established, there are no tools to predict vulnerability to ELA consequences in an individual child. Epigenetic markers including peripheral-cell DNA-methylation profiles may encode ELA and provide predictive outcome markers, yet the interindividual variance of the human genome and rapid changes in DNA methylation in childhood pose significant challenges. Hoping to mitigate these challenges we examined the relation of several ELA dimensions to DNA methylation changes and outcome using a within-subject longitudinal design and a high methylation-change threshold. DNA methylation was analyzed in buccal swab/saliva samples collected twice (neonatally and at 12 months) in 110 infants. We identified CpGs differentially methylated across time for each child and determined whether they associated with ELA indicators and executive function at age 5. We assessed sex differences and derived a sex-dependent 'impact score' based on sites that most contributed to methylation changes. Changes in methylation between two samples of an individual child reflected age-related trends and correlated with executive function years later. Among tested ELA dimensions and life factors including income to needs ratios, maternal sensitivity, body mass index and infant sex, unpredictability of parental and household signals was the strongest predictor of executive function. In girls, high early-life unpredictability interacted with methylation changes to presage executive function. Thus, longitudinal, within-subject changes in methylation profiles may provide a signature of ELA and a potential predictive marker of individual outcome.

Consortium Profile: The Methylation, Imaging and NeuroDevelopment (MIND) Consortium

Epigenetic processes, such as DNA methylation, show potential as biological markers and mechanisms underlying gene-environment interplay in the prediction of mental health and other brain-based phenotypes. However, little is known about how peripheral epigenetic patterns relate to individual differences in the brain itself. An increasingly popular approach to address this is by combining epigenetic and neuroimaging data; yet, research in this area is almost entirely comprised of cross-sectional studies in adults. To bridge this gap, we established the Methylation, Imaging and NeuroDevelopment (MIND) Consortium, which aims to bring a developmental focus to the emerging field of Neuroimaging Epigenetics by (i) promoting collaborative, adequately powered developmental research via multi-cohort analyses; (ii) increasing scientific rigor through the establishment of shared pipelines and open science practices; and (iii) advancing our understanding of DNA methylation-brain dynamics at different developmental periods (from birth to emerging adulthood), by leveraging data from prospective, longitudinal pediatric studies. MIND currently integrates 15 cohorts worldwide, comprising (repeated) measures of DNA methylation in peripheral tissues (blood, buccal cells, and saliva) and neuroimaging by magnetic resonance imaging across up to five time points over a period of up to 21 years (Npooled DNAm = 11,299; Npooled neuroimaging = 10,133; Npooled combined = 4,914). By triangulating associations across multiple developmental time points and study types, we hope to generate new insights into the dynamic relationships between peripheral DNA methylation and the brain, and how these ultimately relate to neurodevelopmental and psychiatric phenotypes.

Childhood Adversities and the ATTACHTM Program's Influence on Immune Cell Gene Expression

OBJECTIVE

To determine whether maternal Adverse Childhood Experiences (ACEs) are (a) associated with increased inflammatory gene expression in mother-child dyads and (b) whether a parenting intervention (ATTACH™) moderates the association between maternal ACEs and mother and/or child inflammatory gene expression.

METHODS

Twenty mother-child dyads, recruited from a domestic violence shelter in Calgary, AB, Canada, were randomized into an ATTACH™ parenting intervention group (n = 9) or a wait-list control group (n = 11). Maternal ACEs were assessed. The mothers and children each provided one non-fasting blood sample after the intervention group completed the ATTACH™ program, which was assayed to quantify the Conserved Transcriptional Response to Adversity (CTRA) score, indicating inflammatory gene expression profile. Mixed-effect linear models were used, separately in mothers and children, to examine the associations between CTRA score, maternal ACEs, and the ACEs-by-intervention group interaction term. The covariates were age, sex, ethnicity, and maternal medication use.

RESULTS

Higher maternal ACEs were associated with higher child CTRA scores (b = 0.123 ± SE 0.044, p = 0.005), indicating an increased pro-inflammatory gene expression profile. The ATTACH™ parenting intervention moderated this association between maternal ACEs and child CTRA scores (b = 0.328 ± SE 0.133, p = 0.014). In mothers, the ACEs-by-intervention interaction terms were insignificant (p = 0.305).

CONCLUSIONS

Maternal ACEs could exert an intergenerational impact on child inflammatory activity, and this association could be moderated by participating in the ATTACH™ parenting intervention.

Maternal sensitivity and child internalizing and externalizing behavior: a mediating role for glucocorticoid receptor gene (NR3C1) methylation?

The early caregiving environment can have lasting effects on child mental health. Animal models suggest that glucocorticoid receptor gene (NR3C1) DNA methylation plays a mediating role in linking more responsive caregiving to improved behavioral outcomes by its impact on the stress regulatory system. In this longitudinal study, we examined whether children's NR3C1 methylation levels mediate an effect of maternal sensitivity in infancy on levels of child internalizing and externalizing behavior in a community sample. Maternal sensitivity of 145 mothers was rated at infant age 5 weeks, 12 months, and 30 months by observing mother-infant interactions. Buccal DNA methylation was assessed in the same children at age 6 years and maternal-reported internalizing and externalizing behavior was assessed at age 6 and 10 years. Higher sensitivity at age 5 weeks significantly predicted lower DNA methylation levels at two NR3C1 CpG loci, although methylation levels at these loci did not mediate an effect of maternal sensitivity on levels of child internalizing and externalizing behavior. Overall, the study provides evidence that maternal sensitivity in early infancy is associated with DNA methylation levels at loci involved in stress regulation, but the significance of this finding for child mental health remains unclear.

Longitudinal patterns of adversity from childhood to adolescence: Examining associations with mental health through emerging adulthood using a random-intercept latent transition analysis

Childhood adversity can have detrimental impacts on life course mental and physical health. Timing, nature, severity, and chronicity of adversity are thought to explain much of the variability in health and developmental outcomes among exposed individuals. The current study seeks to characterize heterogeneity in adverse experiences over time at the individual, family, and neighborhood domains in a cohort of predominantly Black children (85% Black and 15% White, 46.2% girls, 67.2% free/reduced lunch in first grade), and to examine associations with mental health from sixth grade to age 26. Participants were part of a randomized universal preventive interventions trial in first grade with prospective follow-up through early adulthood. Separate models characterized heterogeneity in adversity in elementary, middle, and high schools. Changes in adversity over time and relationships with mental health (anxiety, depression, suicidal behaviors) were investigated using a random-intercept latent transition analysis (RI-LTA). We identified three-class solutions in early childhood, middle school, and high school. Generally, both a higher and a lower poly-adversity class were observed at each time point, with varying nature of adversity characterized by the third class. RI-LTA indicated prevalent within-individual changes in adverse exposure over time and differential associations with mental health and suicidal behaviors. Results suggest that treating adverse exposures as a static construct may limit the ability to characterize salient variation over time. Identifying complexity in adverse experiences and their relation to health and well-being is key for developing and implementing effective prevention and early intervention efforts to mitigate negative effects through the life course. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The peripheral epigenome predicts white matter volume contingent on developmental stage: An ECHO study

Epigenetic processes, including DNA methylation, are emerging as key areas of interest for their potential roles as biomarkers and contributors to the risk of neurodevelopmental, psychiatric, and other brain-based disorders. Despite this growing focus, there remains a notable gap in our understanding of how DNA methylation correlates with individual variations in brain function and structure. Additionally, the dynamics of these relationships during developmental periods, which are critical windows during which many disorders first appear, are still largely unexplored. The current study extends the field by examining if peripheral DNA methylation of myelination-related genes predicts white matter volume in a healthy pediatric population [N = 250; females = 113; age range 2 months-14 years; Mage = 5.14, SDage = 3.60]. We assessed if DNA methylation of 17 myelin-related genes predict white matter volume and if age moderates these relationships. Results highlight low variability in myelin-related epigenetic variance at birth, which rapidly increases non-linearly with age, and that DNA methylation, measured at both the level of a CpG site or gene, is highly predictive of white matter volume, in early childhood but not late childhood. These novel findings propel the field forward by establishing that DNA methylation of myelin-related genes from a peripheral tissue is a predictive marker of white matter volume in children and is influenced by developmental stage. The research underscores the significance of peripheral epigenetic patterns as a proxy for investigating the effects of environmental factors, behaviors, and disorders associated with white matter.

Cumulative Stress Across the Life Course and Biological Aging in Adulthood

OBJECTIVE

Psychosocial stressors have been linked with accelerated biological aging in adults; however, few studies have examined stressors across the life course in relation to biological aging.

METHODS

In 359 individuals (57% White, 34% Black) from the Child Health and Development Studies Disparities study, economic (income, education, financial strain), social (parent-child relations, caretaker responsibilities) and traumatic (death of a sibling or child, violence exposure) stressors were assessed at multiple time points (birth and ages 9, 15, and 50 years). Experiences of major discrimination were assessed at age 50. Life period stress scores were then assessed as childhood (birth-age 15 years) and adulthood (age 50 years). At age 50 years, participants provided blood samples, and DNA methylation was assessed with the EPIC BeadChip. Epigenetic age was estimated using six epigenetic clocks (Horvath, Hannum, Skin and Blood age, PhenoAge, GrimAge, Dunedin Pace of Aging). Age acceleration was determined using residuals from regressing chronologic age on each of the epigenetic age metrics. Telomere length was assessed using the quantitative polymerase chain reaction-based methods.

RESULTS

In linear regression models adjusted for race and gender, total life stress, and childhood and adult stress independently predicted accelerated aging based on GrimAge and faster pace of aging based on the DunedinPace. Associations were attenuated after adjusting for smoking status. In sex-stratified analyses, greater childhood stress was associated with accelerated epigenetic aging among women but not men. No associations were noted with telomere length.

CONCLUSIONS

We found that cumulative stressors across the life course were associated with accelerated epigenetic age, with differences by sex (e.g., accelerated among women). Further research of this association in large and diverse samples is needed.

Mother adversity and co-residence time impact mother-child similarity in genome-wide and gene-specific methylation profiles

BACKGROUND

The effects of adverse life events on physical and psychological health, with DNA methylation (DNAm) as a critical underlying mechanism, have been extensively studied. However, the epigenetic resemblance between mother and child in the context of neglectful caregiving, and whether it may be shaped by the emotional impact of maternal stressful events and the duration of co-residence (indexed by child age), remains unknown. The present study examined mother-child similarity in methylation profiles, considering the potential effect of mother adversity, mother empathy, neglect-control group, child age (an index of years of mother-child co-residence), and mother age. Using Illumina Epic arrays, we quantified DNAm in 115 mother-child saliva samples. We obtained a methylation similarity index by computing correlation coefficients between methylation profiles within dyads, for the entire epigenome, and five specific genes related to stress and empathy: NR3C1, FKPB5, OXTR, SCL6A4, and BDNF.

RESULTS

The methylation profiles of the mother-child familial pairs significantly correlated as compared to mother-child random pairs for the entire epigenome and NR3C1, FKBP5, OXTR and BDNF genes. Next, multiple linear regression models observed associations of mother adversity, child age, and neglect-control group on mother-child methylation similarity, only significant in mother-child familial pairs, after correcting for multiple comparisons. Higher mother adversity was associated with lower mother-child methylation similarity for the epigenome-wide analysis, for the BDNF gene, and in the neglect-control group for the OXTR gene. In turn, being an older child (longer co-residence) was associated with higher mother-child methylation similarity.

CONCLUSIONS

Mother adversity and co-residence time are modulating factors in the intergenerational methylation process that offer a window into development-dependent adaptations that can be affected by both hereditary and environmental factors, significantly observed only in biological dyads. A twofold implication for child well-being emerges, one is positive in that children of mothers exposed to life adversity or neglect did not necessarily inherit their methylation patterns. The other is concerning due to the influence of time spent living together, which affects similarity with the mother and potentially increases the risk of inheriting an epigenetic profile associated with future dysfunctional parenting patterns. This underscores the importance of the 'the earlier, the better' recommendation by the Child Protection System, which is not always followed.

DNA methylation signatures of early-life adversity are exposure-dependent in wild baboons

The early-life environment can profoundly shape the trajectory of an animal's life, even years or decades later. One mechanism proposed to contribute to these early-life effects is DNA methylation. However, the frequency and functional importance of DNA methylation in shaping early-life effects on adult outcomes is poorly understood, especially in natural populations. Here, we integrate prospectively collected data on fitness-associated variation in the early environment with DNA methylation estimates at 477,270 CpG sites in 256 wild baboons. We find highly heterogeneous relationships between the early-life environment and DNA methylation in adulthood: aspects of the environment linked to resource limitation (e.g., low-quality habitat, early-life drought) are associated with many more CpG sites than other types of environmental stressors (e.g., low maternal social status). Sites associated with early resource limitation are enriched in gene bodies and putative enhancers, suggesting they are functionally relevant. Indeed, by deploying a baboon-specific, massively parallel reporter assay, we show that a subset of windows containing these sites are capable of regulatory activity, and that, for 88% of early drought-associated sites in these regulatory windows, enhancer activity is DNA methylation-dependent. Together, our results support the idea that DNA methylation patterns contain a persistent signature of the early-life environment. However, they also indicate that not all environmental exposures leave an equivalent mark and suggest that socioenvironmental variation at the time of sampling is more likely to be functionally important. Thus, multiple mechanisms must converge to explain early-life effects on fitness-related traits.

The Psychoneuroimmunological Model of Moral Distress and Health in Healthcare Workers: Toward Individual and System-Level Solutions

Healthcare is presently experiencing a global workforce crisis, marked by the inability of hospitals to retain qualified healthcare workers. Indeed, poor working conditions and staff shortages have contributed to structural collapse and placed a heavy toll on healthcare workers' (HCWs) well-being, with many suffering from stress, exhaustion, demoralization, and burnout. An additional factor driving qualified HCWs away is the repeated experience of moral distress, or the inability to act according to internally held moral values and perceived ethical obligations due to internal and external constraints. Despite general awareness of this crisis, we currently lack an organized understanding of how stress leads to poor health, wellbeing, and performance in healthcare workers. To address this critical issue, we first review the literature on moral distress, stress, and health in HCWs. Second, we summarize the biobehavioral pathways linking occupational and interpersonal stressors to health in this population, focusing on neuroendocrine, immune, genetic, and epigenetic processes. Third, we propose a novel Psychoneuroimmunological Model of Moral Distress and Health in HCWs based on this literature. Finally, we discuss evidence-based individual- and system-level interventions for preventing stress and promoting resilience at work. Throughout this review, we underscore that stress levels in HCWs are a major public health concern, and that a combination of system-level and individual-level interventions are necessary to address preventable health care harm and foster resilience in this population, including new health policies, mental health initiatives, and additional translational research.

Biomarker-Guided Tailored Therapy in Major Depression

This chapter provides a comprehensive examination of a broad range of biomarkers used for the diagnosis and prediction of treatment outcomes in major depressive disorder (MDD). Genetic, epigenetic, serum, cerebrospinal fluid (CSF), and neuroimaging biomarkers are analyzed in depth, as well as the integration of new technologies such as digital phenotyping and machine learning. The intricate interplay between biological and psychological elements is emphasized as essential for tailoring MDD management strategies. In addition, the evolving link between psychotherapy and biomarkers is explored to uncover potential associations that shed light on treatment response. This analysis underscores the importance of individualized approaches in the treatment of MDD that integrate advanced biological insights into clinical practice to improve patient outcomes.

Within-subject changes in methylome profile identify individual signatures of early-life adversity, with a potential to predict neuropsychiatric outcome

Background

Adverse early-life experiences (ELA), including poverty, trauma and neglect, affect a majority of the world's children. Whereas the impact of ELA on cognitive and emotional health throughout the lifespan is well-established, it is not clear how distinct types of ELA influence child development, and there are no tools to predict for an individual child their vulnerability or resilience to the consequences of ELAs. Epigenetic markers including DNA-methylation profiles of peripheral cells may encode ELA and provide a predictive outcome marker. However, the rapid dynamic changes in DNA methylation in childhood and the inter-individual variance of the human genome pose barriers to identifying profiles predicting outcomes of ELA exposure. Here, we examined the relation of several dimensions of ELA to changes of DNA methylation, using a longitudinal within-subject design and a high threshold for methylation changes in the hope of mitigating the above challenges.

Methods

We analyzed DNA methylation in buccal swab samples collected twice for each of 110 infants: neonatally and at 12 months. We identified CpGs differentially methylated across time, calculated methylation changes for each child, and determined whether several indicators of ELA associated with changes of DNA methylation for individual infants. We then correlated select dimensions of ELA with methylation changes as well as with measures of executive function at age 5 years. We examined for sex differences, and derived a sex-dependent 'impact score' based on sites that most contributed to the methylation changes.

Findings

Setting a high threshold for methylation changes, we discovered that changes in methylation between two samples of an individual child reflected age-related trends towards augmented methylation, and also correlated with executive function years later. Among the tested factors and ELA dimensions, including income to needs ratios, maternal sensitivity, body mass index and sex, unpredictability of parental and household signals was the strongest predictor of executive function. In girls, an interaction was observed between a measure of high early-life unpredictability and methylation changes, in presaging executive function.

Interpretation

These findings establish longitudinal, within-subject changes in methylation profiles as a signature of some types of ELA in an individual child. Notably, such changes are detectable beyond the age-associated DNA methylation dynamics. Future studies are required to determine if the methylation profile changes identified here provide a predictive marker of vulnerabilities to poorer cognitive and emotional outcomes.

A Developmental Psychopathology Perspective on Adverse Childhood Experiences (ACEs): Introduction to the Special Issue

Adverse childhood experiences (ACEs), including child maltreatment and other adversities in the home context and beyond (e.g., witnessing domestic violence; parental mental illness; parental separation; living in a disadvantaged neighborhood) are prevalent in the population and often covary together. Research based on the construct of ACEs has transformed the field of adult mental health, yet child and adolescent mental health has often been overlooked in this work. This special issue of Research on Child and Adolescent Psychopathology focuses on the developmental science of ACEs and child psychopathology. The research presented here draws on the extensive evidence base that now exists regarding the co-occurrence of common childhood adversities, while informing the integration of theory and research on ACEs with that of developmental psychopathology at large. This Introduction provides an overview of ACEs and child mental health from a developmental psychopathology perspective, with an emphasis on key concepts and recent progress spanning the prenatal period through to adolescence and intergenerational pathways. Models of ACEs that emphasize the multi-dimensional nature of adversity and the importance of developmental timing to risk and protective pathways, have played a driving role in this progress. Methodological innovations in this work are highlighted, along with implications for prevention and intervention.

Early origins of health and disease risk: The case for investigating adverse exposures and biological aging in utero, across childhood, and into adolescence

In this article, we suggest that aging and development are two sides of the same coin, and that developing a comprehensive understanding of health and disease risk requires examining age-related processes occurring throughout the earliest years of life. Compared to other periods in life, during this early period of acute vulnerability, when children's biological and regulatory systems are developing, biological aging occurs most rapidly. We review theory and empirical research suggesting that processes of development and aging are intricately linked, and that early adversity may program biological parameters for accelerated aging and disease risk early in life, even though clinical signs of age-related disease onset may not be evident until many years later. Following from this, we make the case for widespread incorporation of biological aging constructs into child development research.

Epigenome-wide meta-analysis of prenatal maternal stressful life events and newborn DNA methylation

Prenatal maternal stressful life events are associated with adverse neurodevelopmental outcomes in offspring. Biological mechanisms underlying these associations are largely unknown, but DNA methylation likely plays a role. This meta-analysis included twelve non-overlapping cohorts from ten independent longitudinal studies (N = 5,496) within the international Pregnancy and Childhood Epigenetics consortium to examine maternal stressful life events during pregnancy and DNA methylation in cord blood. Children whose mothers reported higher levels of cumulative maternal stressful life events during pregnancy exhibited differential methylation of cg26579032 in ALKBH3. Stressor-specific domains of conflict with family/friends, abuse (physical, sexual, and emotional), and death of a close friend/relative were also associated with differential methylation of CpGs in APTX, MyD88, and both UHRF1 and SDCCAG8, respectively; these genes are implicated in neurodegeneration, immune and cellular functions, regulation of global methylation levels, metabolism, and schizophrenia risk. Thus, differences in DNA methylation at these loci may provide novel insights into potential mechanisms of neurodevelopment in offspring.

Next Generation, Modifiable Cardiometabolic Biomarkers: Mitochondrial Adaptation and Metabolic Resilience: A Scientific Statement From the American Heart Association

Cardiometabolic risk is increasing in prevalence across the life span with disproportionate ramifications for youth at socioeconomic disadvantage. Established risk factors and associated disease progression are harder to reverse as they become entrenched over time; if current trends are unchecked, the consequences for individual and societal wellness will become untenable. Interrelated root causes of ectopic adiposity and insulin resistance are understood but identified late in the trajectory of systemic metabolic dysregulation when traditional cardiometabolic risk factors cross current diagnostic thresholds of disease. Thus, children at cardiometabolic risk are often exposed to suboptimal metabolism over years before they present with clinical symptoms, at which point life-long reliance on pharmacotherapy may only mitigate but not reverse the risk. Leading-edge indicators are needed to detect the earliest departure from healthy metabolism, so that targeted, primordial, and primary prevention of cardiometabolic risk is possible. Better understanding of biomarkers that reflect the earliest transitions to dysmetabolism, beginning in utero, ideally biomarkers that are also mechanistic/causal and modifiable, is critically needed. This scientific statement explores emerging biomarkers of cardiometabolic risk across rapidly evolving and interrelated "omic" fields of research (the epigenome, microbiome, metabolome, lipidome, and inflammasome). Connections in each domain to mitochondrial function are identified that may mediate the favorable responses of each of the omic biomarkers featured to a heart-healthy lifestyle, notably to nutritional interventions. Fuller implementation of evidence-based nutrition must address environmental and socioeconomic disparities that can either facilitate or impede response to therapy.

Examination of promotive and protective effects on early adolescent prosocial behavior through a bioecological lens

Introduction

Prosocial behavior during childhood has been associated with numerous positive developmental and behavioral outcomes in adolescence and adulthood. Prosocial behavior, which includes cooperation and helping others, develops within a bioecological context. Considering it through such a lens enhances the understanding of the roles of different bioecological factors in its development.

Methods

Using data from a longitudinal study of adopted children and children reared with their biological parents, this paper examined if positive aspects of a child's bioecological system at age 7 predict prosocial behavior in early adolescence (age 11), and whether these bioecological factors could offset risk due to biological family psychopathology and/or maternal prenatal substance use. The analyses incorporated variables from different levels of Bronfenbrenner's bioecological model (the individual, microsystem, exosystem, and macrosystem) and examined the promotive, and potentially protective, effect of each contextual factor, while also considering their interplay with biological family psychopathology and prenatal substance use.

Results

Results from linear regression models indicated that the microsystem variable of parental warmth at age 7 had a promotive effect on age 11 prosocial behavior. Further, in addition to its main effect, parental warmth was protective against maternal substance use during pregnancy when children were raised with their biological parent (s). Household type (biological family) and biological family internalizing psychopathology were the only other significant predictors in the model, with each associated with lower prosocial behavior at age 11.

Discussion

Study results extend prior work on the benefits of parental warmth on child outcomes by employing a strength-based, bioecological approach to the development of prosocial behavior during early adolescence and examining "for whom" the effects of parental warmth are most protective.

Greater maltreatment severity is associated with smaller brain volume with implication for intellectual ability in young children

Background

Childhood maltreatment profoundly alters trajectories of brain development, promoting markedly increased long-term health risks and impaired intellectual development. However, the immediate impact of maltreatment on brain development in children and the extent to which altered global brain volume contributes to intellectual development in children with maltreatment experience is currently unknown. We here utilized MRI data obtained from children within 6 months after the exposure to maltreatment to assess the association of maltreatment severity with global brain volume changes. We further assessed the association between maltreatment severity and intellectual development and tested for the mediating effect of brain volume on this association.

Method

We used structural MRI (3T) in a sample of 49 children aged 3-5 years with maltreatment exposure, i.e. emotional and physical abuse and/or neglect within 6 months, to characterize intracranial and tissue-specific volumes. Maltreatment severity was coded using the Maternal Interview for the Classification of Maltreatment. IQ was tested at study entry and after one year using the Snijders Oomen Nonverbal Test.

Results

Higher maltreatment severity was significantly correlated with smaller intracranial volume (r = -.393, p = .008), which was mainly driven by lower total brain volume (r = -.393, p = .008), which in turn was primarily due to smaller gray matter volume (r = -.454, p = .002). Furthermore, smaller gray matter volume was associated with lower IQ at study entry (r = -.548, p < .001) and predicted IQ one year later (r = -.493, p = .004.). The observed associations were independent of potential confounding variables, including height, socioeconomic status, age and sex.

Importance

We provide evidence that greater maltreatment severity in early childhood is related to smaller brain size at a very young age with significant consequences for intellectual ability, likely setting a path for far-reaching long-term disadvantages. Insights into the molecular and neural processes that underlie the impact of maltreatment on brain structure and function are urgently needed to derive mechanism-driven targets for early intervention.

The role of mild stressors in children's cognition and inflammation: positive and negative impacts depend on timing of exposure

Although the impact of stressful life events (SLEs) on mental health is well-established, the research on the impact of such stressors on cognitive outcomes has produced mixed results. Arguably, the timing and severity of exposure may play a key role. In this study, we shed light on the relationship between timing of exposure to relatively minor SLEs and cognitive ability in children, while taking into account the role of a plausible biological mediator: inflammation. Using data from the Avon Longitudinal Study of Parents and Children, a general population birth cohort, we explored the role of relatively minor SLEs, experienced during two crucial developmental stages: up to transition to school (1-4.5 years) and up to transition to puberty (5.5-8.5 years). We then tested if they may impact differently on inflammatory markers (serum C-reactive protein [CRP] and interleukin 6 [IL-6]) at age 9 and general intelligence, measured with the Wechsler Abbreviated Scale of Intelligence at age 15. Data (n = 4,525) were analyzed using path analysis while controlling for covariates. We found that when relatively minor stressful events were experienced up to transition to school they were significantly associated with higher IQ at age 15, whereas when experienced up to transition to puberty they were significantly associated with higher levels of IL-6 at age 9. Results were robust to adjustment for relevant covariates, including IQ at age 8. Mild stressors in childhood may result in positive (i.e., improved cognition) or negative (i.e., inflammation) outcomes depending on the timing of exposure.

Prevention of Childhood Adversities and Children's Common Mental Disorders and School Grades

Importance

Adversity during childhood can limit children's chances of achieving their optimal developmental and psychological outcomes. Well-designed observational studies might help identify adversities that are most implicated in this, thereby helping to identify potential targets for developing interventions.

Objective

To compare the association between preventing childhood poverty, parental mental illness and parental separation, and the population rate of offspring common mental disorders (ages 16-21 years) or average school grades (age 16 years).

Design, Setting, and Participants

A population-based, longitudinal cohort study using Swedish registries was conducted. A total of 163 529 children born in Sweden between January 1, 1996, and December 31, 1997, were followed up until their 21st birthday. They were linked to registries using Sweden's national personal identification number. Children were linked to birth parents, hospital records, and school data. Parents were linked to registries containing health, income, sociodemographic, and obstetric data. Analyses were conducted between January 10, 2021, and August 26, 2022.

Exposures

Childhood adversities of relative poverty (household disposable income <50% of the median), parental inpatient admission for a mental illness, or parental separation. Adversities were categorized into developmental periods: ages 0 to 3, 4 to 7, 8 to 11, and 12 to 16 years.

Main Outcomes and Measures

The main outcomes were children's hospital records with a diagnosis of anxiety or depression between ages 16 and 21 years and school grades at the end of compulsory education (age 16 years). The parametric g-formula modeled population changes in outcomes associated with the counterfactual, hypothetical preventing adversity exposures, accounting for fixed and time-varying confounders. Adjustments were made for parental demographic characteristics, obstetric variables, and socioeconomic data at birth.

Results

A total of 163 529 children were included in the cohort (51.2% boys, 51.4% born in 1996). Preventing all adversities was associated with an estimated change in the prevalence of offspring common mental disorders from 10.2% to 7.6% and an improvement in school grades with an SD of 0.149 (95% CI, 0.147-0.149). Preventing parental separation provided for the greatest improvement, with an estimated 2.34% (95% CI, 2.23%-2.42%) fewer children with a common mental disorder and an improvement in school grades by 0.127 SDs (0.125-0.129). Greater improvements were shown by hypothetically targeting adolescents (age 12-16 years) and those whose parents had a mental illness when the child was born.

Conclusions and Relevance

The results of this cohort modeling study suggest that preventing childhood adversity could provide notable improvements in the rates of common mental disorders and school grades. Many children might achieve better life outcomes if resources are properly allocated to the right adversities (parental separation), the right groups (children with parental mental illness), and at the right time (adolescence).

Does Timing Matter? Associations Between Intimate Partner Violence Across the Early Life Course and Internalizing and Externalizing Behavior in Children

The association between exposure to intimate partner violence (IPV) and child behavior problems is well established. However, questions remain about whether the timing during the child's early life course matters. We used a structured life course approach to investigate associations between the timing of IPV and children's internalizing and externalizing behaviors. Participants were from the Australian Longitudinal Study on Women's Health (ALSWH), a national, randomly sampled community-based study that has surveyed women every 3 years since 1996. For this study, mothers born 1973 to 1978 (N = 2,163) provided data on their three youngest children under 13 years (N = 3,697, 48.5% female) as part of the Mothers and their Children's Health (MatCH) study in 2016/2017. Mothers indicated IPV in ALSWH using the Community Composite Abuse Scale in early (M = 0.99 years, SD = 0.88 years) and middle childhood (M = 3.98 years, SD = 0.92 years), and before birth (preconception). Mothers rated child internalizing and externalizing behavior in MatCH (child age: M = 8.15 years, SD = 2.37 years) using the Strengths and Difficulties Questionnaire. We tested critical period, sensitive period, and accumulation hypotheses by comparing the fit of nested linear regression models (separately for girls and boys). Mothers were predominantly Caucasian (>90%) and university educated (65.5%), and 41.7% reported financial stress. Most children were not exposed to IPV (68.1%). Of those who were, 55.2% were exposed at one time, 28.7% at two times, and 16.1% at all three. Accumulation was the best model for externalizing in boys and girls and for internalizing in girls. A critical period in middle childhood was identified for internalizing in boys. Overall, the duration of exposure was more important than the timing. This suggests early detection is essential in mitigating the impact of IPV on children, with particular attention needed for boys exposed to IPV in middle childhood.

Stage 2 Registered Report: Epigenetic Intergenerational Transmission: Mothers' Adverse Childhood Experiences and DNA Methylation

OBJECTIVE

Individual differences in risk for mental disorders over the lifespan are shaped by forces acting before the individual is born-in utero, but likely even earlier, during the mother's own childhood. The environmental epigenetics hypothesis proposes that sustained effects of environmental conditions on gene expression are mediated by epigenetic mechanisms. Recent human studies have shown that adversities in childhood are correlated with DNA methylation (DNAm) in adulthood. In the current study, we tested the following pre-registered hypotheses: Mothers' adverse childhood experiences (ACEs) are correlated with DNAm in peripheral blood during pregnancy (hypothesis 1) and in cord blood samples from newborn infants (hypothesis 2), and women's depression and anxiety symptoms during pregnancy mediate the association between mothers' ACE exposure and prenatal/neonatal DNA methylation (hypothesis 3).

METHOD

Data were from the Avon Longitudinal Study of Parents and Children Accessible Resource for Integrated Epigenomic Studies substudy. Women provided retrospective self-reports during pregnancy of ACE exposure. We conducted an epigenome-wide association study testing whether mothers' ACE exposure, cumulative score (0-10), was associated with DNAm in maternal antenatal blood and infant cord blood in more than 450,000 CpG (point on DNA sequence where cytosine and guanine base pairs are linked by a phosphate, where methylation usually occurs) sites on the Illumina 450K BeadChip. Analyses for cord blood were separated by infant sex, a pre-registered analysis.

RESULTS

Hypothesis 1: In 896 mother-infant pairs with available methylation and ACE exposure data, there were no significant associations between mothers' ACE score and DNAm from antenatal peripheral blood, after controlling for covariates. Hypothesis 2: In infant cord blood, there were 5 CpG sites significantly differentially methylated in relation to mothers' ACEs (false discovery rate [FDR] < .05), but only in male offspring. Effect sizes were medium, with partial eta squared values ranging from 0.060 to 0.078. CpG sites were in genes related to mitochondrial function and neuronal development in the cerebellum. Hypothesis 3: There was no mediation by maternal anxiety/depression symptoms found between mothers' ACEs score and DNAm in the significant CpG sites in male cord blood. Mediation was not tested in antenatal peripheral blood, because no direct association between mothers' ACE score and antenatal peripheral blood was found.

CONCLUSION

Our results show that mothers' ACE exposure is associated with DNAm in male offspring, supporting the notion that DNAm could be a marker of intergenerational biological embedding of mothers' childhood adversity.

STUDY REGISTRATION INFORMATION

Epigenetic Intergenerational Transmission: Mothers' Adverse Childhood Experiences and DNA Methylation; https://doi.org/10.1016/j.jaac.2020.03.008.

Early life adversities and lifelong health outcomes: A review of the literature on large, social, long-lived nonhuman mammals

Social nonhuman animals are powerful models for studying underlying factors related to lifelong health outcomes following early life adversities (ELAs). ELAs can be linked to lifelong health outcomes depending on the species, system, sensitive developmental periods, and biological pathways. This review focuses on the literature surrounding ELAs and lifelong health outcomes in large, social, relatively long-lived nonhuman mammals including nonhuman primates, canids, hyenas, elephants, ungulates, and cetaceans. These mammals, like humans but unlike the most-studied rodent models, have longer life histories, complex social structures, larger brains, and comparable stress and reproductive physiology. Collectively, these features make them compelling models for comparative aging research. We review studies of caregiver, social, and ecological ELAs, often in tandem, in these mammals. We consider experimental and observational studies and what each has contributed to our knowledge of health across the lifespan. We demonstrate the continued and expanded need for comparative research to inform about the social determinants of health and aging in both humans and nonhuman animals.

Epigenetic regulation in major depression and other stress-related disorders: molecular mechanisms, clinical relevance and therapeutic potential

Major depressive disorder (MDD) is a chronic, generally episodic and debilitating disease that affects an estimated 300 million people worldwide, but its pathogenesis is poorly understood. The heritability estimate of MDD is 30-40%, suggesting that genetics alone do not account for most of the risk of major depression. Another factor known to associate with MDD involves environmental stressors such as childhood adversity and recent life stress. Recent studies have emerged to show that the biological impact of environmental factors in MDD and other stress-related disorders is mediated by a variety of epigenetic modifications. These epigenetic modification alterations contribute to abnormal neuroendocrine responses, neuroplasticity impairment, neurotransmission and neuroglia dysfunction, which are involved in the pathophysiology of MDD. Furthermore, epigenetic marks have been associated with the diagnosis and treatment of MDD. The evaluation of epigenetic modifications holds promise for further understanding of the heterogeneous etiology and complex phenotypes of MDD, and may identify new therapeutic targets. Here, we review preclinical and clinical epigenetic findings, including DNA methylation, histone modification, noncoding RNA, RNA modification, and chromatin remodeling factor in MDD. In addition, we elaborate on the contribution of these epigenetic mechanisms to the pathological trait variability in depression and discuss how such mechanisms can be exploited for therapeutic purposes.

Reactivation of Early-Life Stress-Sensitive Neuronal Ensembles Contributes to Lifelong Stress Hypersensitivity

Early-life stress (ELS) is one of the strongest lifetime risk factors for depression, anxiety, suicide, and other psychiatric disorders, particularly after facing additional stressful events later in life. Human and animal studies demonstrate that ELS sensitizes individuals to subsequent stress. However, the neurobiological basis of such stress sensitization remains largely unexplored. We hypothesized that ELS-induced stress sensitization would be detectable at the level of neuronal ensembles, such that cells activated by ELS would be more reactive to adult stress. To test this, we leveraged transgenic mice to genetically tag, track, and manipulate experience-activated neurons. We found that in both male and female mice, ELS-activated neurons within the nucleus accumbens (NAc), and to a lesser extent the medial prefrontal cortex, were preferentially reactivated by adult stress. To test whether reactivation of ELS-activated ensembles in the NAc contributes to stress hypersensitivity, we expressed hM4Dis receptor in control or ELS-activated neurons of pups and chemogenetically inhibited their activity during experience of adult stress. Inhibition of ELS-activated NAc neurons, but not control-tagged neurons, ameliorated social avoidance behavior following chronic social defeat stress in males. These data provide evidence that ELS-induced stress hypersensitivity is encoded at the level of corticolimbic neuronal ensembles.SIGNIFICANCE STATEMENT Early-life stress enhances sensitivity to stress later in life, yet the mechanisms of such stress sensitization are largely unknown. Here, we show that neuronal ensembles in corticolimbic brain regions remain hypersensitive to stress across the life span, and quieting these ensembles during experience of adult stress rescues stress hypersensitivity.

Epigenome-wide association study of incident type 2 diabetes in Black and White participants from the Atherosclerosis Risk in Communities Study

DNA methylation studies of incident type 2 diabetes in US populations are limited, and to our knowledge none included individuals of African descent living in the US. We performed an epigenome-wide association analysis of blood-based methylation levels at CpG sites with incident type 2 diabetes using Cox regression in 2,091 Black and 1,029 White individuals from the Atherosclerosis Risk in Communities study. At an epigenome-wide significance threshold of 10-7, we detected 7 novel diabetes-associated CpG sites in C1orf151 (cg05380846: HR= 0.89, p = 8.4 × 10-12), ZNF2 (cg01585592: HR= 0.88, p = 1.6 × 10-9), JPH3 (cg16696007: HR= 0.87, p = 7.8 × 10-9), GPX6 (cg02793507: HR= 0.85, p = 2.7 × 10-8 and cg00647063: HR= 1.20, p = 2.5 × 10-8), chr17q25 (cg16865890: HR= 0.8, p = 6.9 × 10-8), and chr11p15 (cg13738793: HR= 1.11, p = 7.7 × 10-8). The CpG sites at C1orf151, ZNF2, JPH3 and GPX6, were identified in Black adults, chr17q25 was identified in White adults, and chr11p15 was identified upon meta-analyzing the two groups. The CpG sites at JPH3 and GPX6 were likely associated with incident type 2 diabetes independent of BMI. All the CpG sites, except at JPH3, were likely consequences of elevated glucose at baseline. We additionally replicated known type 2 diabetes-associated CpG sites including cg19693031 at TXNIP, cg00574958 at CPT1A, cg16567056 at PLBC2, cg11024682 at SREBF1, cg08857797 at VPS25, and cg06500161 at ABCG1, 3 of which were replicated in Black adults at the epigenome-wide threshold. We observed modest increase in type 2 diabetes variance explained upon addition of the significantly associated CpG sites to a Cox model that included traditional type 2 diabetes risk factors and fasting glucose (increase from 26.2% to 30.5% in Black adults; increase from 36.9% to 39.4% in White adults). We examined if groups of proximal CpG sites were associated with incident type 2 diabetes using a gene-region specific and a gene-region agnostic differentially methylated region (DMR) analysis. Our DMR analyses revealed several clusters of significant CpG sites, including a DMR consisting of a previously discovered CpG site at ADCY7 and promoter regions of TP63 which were differentially methylated across all race groups. This study illustrates improved discovery of CpG sites/regions by leveraging both individual CpG site and DMR analyses in an unexplored population. Our findings include genes linked to diabetes in experimental studies (e.g., GPX6, JPH3, and TP63), and future gene-specific methylation studies could elucidate the link between genes, environment, and methylation in the pathogenesis of type 2 diabetes.

Sensitive periods for exposure to indoor air pollutants and psychosocial factors in association with symptoms of psychopathology at school-age in a South African birth cohort

Background

Gestation and the first few months of life are important periods for brain development. During these periods, exposure to environmental toxicants and psychosocial stressors are particularly harmful and may impact brain development. Specifically, exposure to indoor air pollutants (IAP) and psychosocial factors (PF) during these sensitive periods has been shown to predict childhood psychopathology.

Objectives

This study aims to investigate sensitive periods for the individual and joint effects of IAP and PF on childhood psychopathology at 6.5 years.

Methods

We analyzed data from the Drakenstein Child Health Study (N=599), a South African birth cohort. Exposure to IAP and PF was measured during the second trimester of pregnancy and 4 months postpartum. The outcome of childhood psychopathology was assessed at 6.5 years old using the Childhood Behavior Checklist (CBCL). We investigated individual effects of either pre-or postnatal exposure to IAP and PF on CBCL scores using adjusted linear regression models, and joint effects of these exposures using quantile g-computation and self-organizing maps (SOM). To identify possible sensitive periods, we used a structured life course modeling approach (SLCMA) as well as exposure mixture methods (quantile g-computation and SOM).

Results

Prenatal exposure to IAP or PFs, as well as the total prenatal mixture assessed using quantile g-computation, were associated with increased psychopathology. SLCMA and SOM models also indicated that the prenatal period is a sensitive period for IAP exposure on childhood psychopathology. Depression and alcohol were associated in both the pre-and postnatal period, while CO was associated with the postnatal period.

Discussion

Pregnancy may be a sensitive period for the effect of indoor air pollution on childhood psychopathology. Exposure to maternal depression and alcohol in both periods was also associated with psychopathology. Determining sensitive periods of exposure is vital to ensure effective interventions to reduce childhood psychopathology.

Association between the timing of childhood adversity and epigenetic patterns across childhood and adolescence: findings from the Avon Longitudinal Study of Parents and Children (ALSPAC) prospective cohort

BACKGROUND

Childhood adversity is a potent determinant of health across development and is associated with altered DNA methylation signatures, which might be more common in children exposed during sensitive periods in development. However, it remains unclear whether adversity has persistent epigenetic associations across childhood and adolescence. We aimed to examine the relationship between time-varying adversity (defined through sensitive period, accumulation of risk, and recency life course hypotheses) and genome-wide DNA methylation, measured three times from birth to adolescence, using data from a prospective, longitudinal cohort study.

METHODS

We first investigated the relationship between the timing of exposure to childhood adversity between birth and 11 years and blood DNA methylation at age 15 years in the Avon Longitudinal Study of Parents and Children (ALSPAC) prospective cohort study. Our analytic sample included ALSPAC participants with DNA methylation data and complete childhood adversity data between birth and 11 years. We analysed seven types of adversity (caregiver physical or emotional abuse, sexual or physical abuse [by anyone], maternal psychopathology, one-adult households, family instability, financial hardship, and neighbourhood disadvantage) reported by mothers five to eight times between birth and 11 years. We used the structured life course modelling approach (SLCMA) to identify time-varying associations between childhood adversity and adolescent DNA methylation. Top loci were identified using an R2 threshold of 0·035 (ie, ≥3·5% of DNA methylation variance explained by adversity). We attempted to replicate these associations using data from the Raine Study and Future of Families and Child Wellbeing Study (FFCWS). We also assessed the persistence of adversity-DNA methylation associations we previously identified from age 7 blood DNA methylation into adolescence and the influence of adversity on DNA methylation trajectories from ages 0-15 years.

FINDINGS

Of 13 988 children in the ALSPAC cohort, 609-665 children (311-337 [50-51%] boys and 298-332 [49-50%] girls) had complete data available for at least one of the seven childhood adversities and DNA methylation at 15 years. Exposure to adversity was associated with differences in DNA methylation at 15 years for 41 loci (R2 ≥0·035). Sensitive periods were the most often selected life course hypothesis by the SLCMA. 20 (49%) of 41 loci were associated with adversities occurring between age 3 and 5 years. Exposure to one-adult households was associated with differences in DNA methylation at 20 [49%] of 41 loci, exposure to financial hardship was associated with changes at nine (22%) loci, and physical or sexual abuse was associated with changes at four (10%) loci. We replicated the direction of associations for 18 (90%) of 20 loci associated with exposure to one-adult household using adolescent blood DNA methylation from the Raine Study and 18 (64%) of 28 loci using saliva DNA methylation from the FFCWS. The directions of effects for 11 one-adult household loci were replicated in both cohorts. Differences in DNA methylation at 15 years were not present at 7 years and differences identified at 7 years were no longer apparent by 15 years. We also identified six distinct DNA methylation trajectories from these patterns of stability and persistence.

INTERPRETATION

These findings highlight the time-varying effect of childhood adversity on DNA methylation profiles across development, which might link exposure to adversity to potential adverse health outcomes in children and adolescents. If replicated, these epigenetic signatures could ultimately serve as biological indicators or early warning signs of initiated disease processes, helping identify people at greater risk for the adverse health consequences of childhood adversity.

FUNDING

Canadian Institutes of Health Research, Cohort and Longitudinal Studies Enhancement Resources, EU's Horizon 2020, US National Institute of Mental Health.

Testing lifecourse theories characterising associations between maternal depression and offspring depression in emerging adulthood: the Avon Longitudinal Study of Parents and Children

BACKGROUND

Maternal depression is a major determinant of offspring mental health. Yet, little is understood about how the duration and timing of maternal depression shapes youth risk for depressive symptoms, which if understood could inform when best to intervene. This study aimed to determine how the timing and duration of maternal depression was related to offspring depression in emerging adulthood, and if these associations varied by sex.

METHODS

We analysed data from the Avon Longitudinal Study of Parents and Children (a prenatal cohort in the Avon area of England, 1991-2003), n = 3,301. We applied the structured lifecourse modelling approach to maternal depression (assessed at 13 points from prenatal period to adolescence) and emerging adult depressive symptoms (age 21). Lifecourse models assessed were accumulation (sum of timepoints when maternal depression was reported), sensitive periods (each period assessed as one during which maternal depression has a stronger effect) and instability (frequent fluctuations in maternal depression).

RESULTS

Female adolescents (n = 2,132) had higher SMFQ scores (mean = 6.15, SD = 5.90) than males (n = 1,169, mean = 4.87, SD = 4.82). Maternal depression was most common in the infancy period (21.2% males; 21.4% females). For males, accumulation was the most appropriate lifecourse model; for each additional period of maternal depression, depressive symptoms in emerging adulthood increased by 0.11 (95% CI: 0.07, 0.15, one-sided p value ≤ .001). For females, exposure to maternal depression was associated with increasing depressive symptoms in emerging adulthood, with the largest effect in mid-childhood (increase of 0.27 units, 95% CI 0.03-0.50, p = .015 for difference between mid-childhood and other time-periods) and a smaller, equal effect at all other time-periods (increase of 0.07 units per time-period, 95% CI: 0.03-0.12, p = .002).

CONCLUSIONS

This study highlights the importance of ongoing maternal depression for the development of depression in offspring through to emerging adulthood. Because long-term exposure to maternal depression was particularly important, early interventions are warranted.

Trajectories of cortical structures associated with stress across adolescence: a bivariate latent change score approach

BACKGROUND

Stress exposure in childhood and adolescence has been linked to reductions in cortical structures and cognitive functioning. However, to date, most of these studies have been cross-sectional, limiting the ability to make long-term inferences, given that most cortical structures continue to develop through adolescence.

METHODS

Here, we used a subset of the IMAGEN population cohort sample (N = 502; assessment ages: 14, 19, and 22 years; mean age: 21.945 years; SD = 0.610) to understand longitudinally the long-term interrelations between stress, cortical development, and cognitive functioning. To these ends, we first used a latent change score model to examine four bivariate relations - assessing individual differences in change in the relations between adolescent stress exposure and volume, surface area, and cortical thickness of cortical structures, as well as cognitive outcomes. Second, we probed for indirect neurocognitive effects linking stress to cortical brain structures and cognitive functions using rich longitudinal mediation modeling.

RESULTS

Latent change score modeling showed that greater baseline adolescence stress at age 14 predicted a small reduction in the right anterior cingulate volume (Std. β = -.327, p = .042, 95% CI [-0.643, -0.012]) and right anterior cingulate surface area (Std. β = -.274, p = .038, 95% CI [-0.533, -0.015]) across ages 14-22. These effects were very modest in nature and became nonsignificant after correcting for multiple comparisons. Our longitudinal analyses found no evidence of indirect effects in the two neurocognitive pathways linking adolescent stress to brain and cognitive outcomes.

CONCLUSION

Findings shed light on the impact of stress on brain reductions, particularly in the prefrontal cortex that have consistently been implicated in the previous cross-sectional studies. However, the magnitude of effects observed in our study is smaller than that has been reported in past cross-sectional work. This suggests that the potential impact of stress during adolescence on brain structures may likely be more modest than previously noted.

Epigenetic clocks and research implications of the lack of data on whom they have been developed: a review of reported and missing sociodemographic characteristics

Epigenetic clocks are increasingly being used as a tool to assess the impact of a wide variety of phenotypes and exposures on healthy ageing, with a recent focus on social determinants of health. However, little attention has been paid to the sociodemographic characteristics of participants on whom these clocks have been based. Participant characteristics are important because sociodemographic and socioeconomic factors are known to be associated with both DNA methylation variation and healthy ageing. It is also well known that machine learning algorithms have the potential to exacerbate health inequities through the use of unrepresentative samples - prediction models may underperform in social groups that were poorly represented in the training data used to construct the model. To address this gap in the literature, we conducted a review of the sociodemographic characteristics of the participants whose data were used to construct 13 commonly used epigenetic clocks. We found that although some of the epigenetic clocks were created utilizing data provided by individuals from different ages, sexes/genders, and racialized groups, sociodemographic characteristics are generally poorly reported. Reported information is limited by inadequate conceptualization of the social dimensions and exposure implications of gender and racialized inequality, and socioeconomic data are infrequently reported. It is important for future work to ensure clear reporting of tangible data on the sociodemographic and socioeconomic characteristics of all the participants in the study to ensure that other researchers can make informed judgements about the appropriateness of the model for their study population.

The oxytocin receptor rs2254298 polymorphism and alcohol withdrawal symptoms: a gene-environment interaction in mood disorders

Objective

Alcohol use disorder (AUD) is a common mental disorder characterized by repeated withdrawal episodes. Negative emotions during withdrawal are the primary factors affecting successful abstinence. Oxytocin is a critical modulator of emotions. OXTR, the oxytocin receptor, may also be a promising candidate for treating alcohol withdrawal symptoms. Previous studies indicated that people with different genotypes of OXTR rs2254298 were reported to suffer from more significant depressive or heightened anxiety symptoms when experiencing early adversity. The present study aims to explore the modulatory role of the polymorphism OXTR rs2254298 on mood disorders during alcohol withdrawal and to help researchers better understand and develop effective relapse prevention and interventions for alcohol use disorders.

Methods

We recruited 265 adult Chinese Han men with AUD. Anxiety and depressive symptoms were measured using the Self-Rating Anxiety Scale and Self-Rating Depression Scale. Alcohol dependence levels were measured using Michigan Alcoholism Screening Test. Genomic DNA extraction and genotyping from participants' peripheral blood samples.

Result

First, a multiple linear regression was used to set the alcohol dependence level, OXTR.rs2254298, interaction terms as the primary predictor variable, and depression or anxiety as an outcome; age and educational years were covariates. There was a significant interaction between OXTR rs2254298 and alcohol dependence level on anxiety (B = 0.23, 95% confidence interval [CI]: 0.01-0.45) but not on depression (B = -0.06, 95% CI: -0.30 - 0.18). The significance region test showed that alcohol-dependent men who are GG homozygous were more likely to experience anxiety symptoms than subjects with the A allele (A allele: β = 0.27, p < 0.001; GG homozygote: β = 0.50, p < 0.001). Finally, re-parameterized regression analysis demonstrated that this gene-environment interaction of OXTR rs2254298 and alcohol dependence on anxiety fits the weak differential susceptibility model (R² = 0.17, F (5,259) = 13.46, p < 0.001).

Conclusion

This study reveals a gene-environment interactive effect between OXTR rs2254298 and alcohol withdrawal on anxiety but not depression. From the perspective of gene-environment interactions, this interaction fits the differential susceptibility model; OXTR rs2254298 GG homozygote carriers are susceptible to the environment and are likely to experience anxiety symptoms of alcohol withdrawal.

A systematic review of neuroimaging epigenetic research: calling for an increased focus on development

Epigenetic mechanisms, such as DNA methylation (DNAm), have gained increasing attention as potential biomarkers and mechanisms underlying risk for neurodevelopmental, psychiatric and other brain-based disorders. Yet, surprisingly little is known about the extent to which DNAm is linked to individual differences in the brain itself, and how these associations may unfold across development - a time of life when many of these disorders emerge. Here, we systematically review evidence from the nascent field of Neuroimaging Epigenetics, combining structural or functional neuroimaging measures with DNAm, and the extent to which the developmental period (birth to adolescence) is represented in these studies. We identified 111 articles published between 2011-2021, out of which only a minority (21%) included samples under 18 years of age. Most studies were cross-sectional (85%), employed a candidate-gene approach (67%), and examined DNAm-brain associations in the context of health and behavioral outcomes (75%). Nearly half incorporated genetic data, and a fourth investigated environmental influences. Overall, studies support a link between peripheral DNAm and brain imaging measures, but there is little consistency in specific findings and it remains unclear whether DNAm markers present a cause, correlate or consequence of brain alterations. Overall, there is large heterogeneity in sample characteristics, peripheral tissue and brain outcome examined as well as the methods used. Sample sizes were generally low to moderate (median nall = 98, ndevelopmental = 80), and attempts at replication or meta-analysis were rare. Based on the strengths and weaknesses of existing studies, we propose three recommendations on how advance the field of Neuroimaging Epigenetics. We advocate for: (1) a greater focus on developmentally oriented research (i.e. pre-birth to adolescence); (2) the analysis of large, prospective, pediatric cohorts with repeated measures of DNAm and imaging to assess directionality; and (3) collaborative, interdisciplinary science to identify robust signals, triangulate findings and enhance translational potential.