Socially stratified DNA-methylation profiles are associated with disparities in child and adolescent mental health
Authors: Raffington L. , Tanksley P. , Vinnik L. , Sabhlok A. , Patterson M.W. , Mallard T. , Malanchini M. , Ayorech Z. , Tucker-Drob E.M. , Harden K.P. 
Published: September 2021

Importance

Economic and racial inequality is linked to disparities in children’s mental health. Biomarkers that reflect these social disparities are lacking.

Objective

We examined the hypothesis that salivary DNA-methylation patterns of higher inflammation and faster pace of biological aging are economically, racially and ethnically stratified and are associated with child mental health.

Design

The Texas Twin Project is an on-going, observational, longitudinal study that began in May 2012. Analyses were preregistered on May 7, 2021, and completed on August 23, 2021.

Setting

The population-based study identified and recruited participants from public school rosters in the greater Austin area.

Participants

Participants in the analytic data set included all participants that agreed to contribute DNA samples and whose samples were assayed by January 2021.

Exposures

Family- and neighborhood-level socioeconomic inequality, racial and ethnic identities (White, Latinx, Black, Asian).

Main Measure(s)

Environmental exposures were analyzed in relation to salivary DNA- methylation profiles of higher inflammation (DNAm-CRP) and faster pace of biological aging (DunedinPoAm). Child internalizing problems, attention problems, aggression, rule-breaking, ADHD, oppositional defiant disorder, and conduct disorder were measured using parent-reports and self-reports on abbreviated versions of the Achenbach Child Behavior Checklist and Conners 3.The hypotheses being tested were formulated after data collection of the present data freeze and were pre-registered prior to analyses being conducted.

Results

In a sample of N=1,183 8-to-19-year-olds (609 female, age M=13.38y), children’s salivary DNA-methylation profiles and psychiatric symptoms differed by socioeconomic conditions, race and ethnicity. Children with more parent-reported internalizing symptoms had higher DNAm-CRP (r=0.15, 95% CI=0.05 to 0.25, P=0.004) and DunedinPoAm (r=0.15, CI=0.05 to 0.25, P=0.002), and children with more parent-reported aggression problems had higher DNAm-CRP (r=0.17, CI=0.04 to 0.31, P=0.013). DNAm-CRP partially mediated advantage of higher family socioeconomic status (16% of total effect) and White racial identity (12% of total effect) on reduced internalizing symptoms. DunedinPoAm also partially mediated advantage of White racial identity on internalizing (19% of total effect).

Conclusions and Relevance

Socioeconomic and racial inequality are visible in children’s epigenetic profiles of inflammation and the rate of biological aging in a manner that is tied to social disparities in mental health.

Key Points

Question

We examined whether salivary DNA-methylation profiles are socially stratified and associated with child mental health.

Findings

In this preregistered, cross-sectional observational study of 1,183 children and adolescents, socioeconomic, racial, and ethnic disparities in mental health were associated with salivary DNA-methylation profiles of inflammation and the pace of biological aging.

Meaning

DNA-methylation biomarkers hold promise as tools to quantify the biological impact of socioeconomic inequality and being racially minoritized in a manner that is tied to social disparities in mental health.