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.

Pregnancy and Infant Development (PRIDE)-a preliminary observational study of maternal adversity and infant development

Background

Children from socioeconomically disadvantaged families have a markedly elevated risk for impaired cognitive and social-emotional development. Children in poverty experience have a high risk for developmental delays. Poverty engenders disproportionate exposure to psychological adversity which may contribute to impaired offspring development; however the effect may be mitigated by social support and other aspects of resilience. Our objective was to determine the association between maternal stress, adversity and social support and early infant neurobehavior and child behavior at two and three years.

Methods

We conducted a longitudinal mother-infant cohort study nested within a regional home visiting program in Cincinnati, Ohio. Four home study visits were completed to collect measures of maternal stress, adversity and social support and infant and child behavior. A measure of infant neurobehavior (‘high-arousal’ infant) was derived from the NICU Network Neurobehavioral Scale (NNNS) at 1 month and externalizing and internalizing symptoms were measured by the Child Behavior Checklist (CBCL) at 24 and 36 months. Linear and logistic regression identified associations between maternal risk/protective factors and infant and child behavioral measures. We used stratification and multiplicative interaction terms to examine potential interactions.

Results

We enrolled n = 55 pregnant mothers and follow 53 mother–offspring dyads at 1 month, 40 dyads at 24 months and 27 dyads at 36 months. Maternal adversity and protective factors were not associated with neurobehavior at one month. However, maternal depression and measures of distress in pregnancy were significantly associated with internalizing and externalizing symptoms at 24 and 36 months.

Conclusions

This pilot study established the feasibility of conducting longitudinal research within a community intervention program. In addition, although there were no statistically significant associations between maternal psychosocial factors in pregnancy and infant neurobehavior, there were several associations at 24 months, primarily internalizing symptoms, which persisted through 36 months. Future work will replicate findings within a larger study as well as explore mediators and modifiers of these associations.

The joint contribution of maternal history of early adversity and adulthood depression to socioeconomic status and potential relevance for offspring development

BACKGROUND

We examined the interactive effects of maternal childhood adversity and later adulthood depression on subsequent socioeconomic status (SES).

METHODS

Our community sample ranged from 230 to 243 mothers (across measures) drawn from a prospective, longitudinal cohort study. Maternal childhood adversity scores were derived using an integrated measure derived from the Childhood Trauma Questionnaire (CTQ) and the Parental Bonding Index (PBI). Maternal depression was measured in the prenatal period with the Center for Epidemiologic Studies Depression Scale (CES-D). SES measures included maternal highest level of education and family income as obtained prenatally.

RESULTS

The analyses yielded significant interaction effects between maternal childhood adversity and prenatal depression that predicted income, prenatally. Women who reported higher levels of childhood adversity combined with higher levels of self-reported depressive symptoms were significantly more likely to live in low SES environments. Results also showed that level of education was predicted by childhood adversity independent of maternal symptoms of depression.

CONCLUSION

The results suggest that SES is influenced by a life course pathway that begins in childhood and includes adversity-related mental health outcomes. Since child health and development is influenced by both maternal mental health and SES, this pathway may also contribute to the intergenerational transmission of the risk for psychopathology in the offspring. The results also emphasize the importance of studying potential precursors of low SES, a well-documented environmental risk factor for poor developmental outcomes in the offspring.