Early Experiences of Threat, but Not Deprivation, Are Associated With Accelerated Biological Aging in Children and Adolescents

Abstract

Background: Recent conceptual models argue that early life adversity (ELA) accelerates development, which may contribute to poor mental and physical health outcomes. Evidence for accelerated development in youths comes from studies of telomere shortening or advanced pubertal development following circumscribed ELA experiences and neuroimaging studies of circuits involved in emotional processing. It is unclear whether all ELA is associated with accelerated development across global metrics of biological aging or whether this pattern emerges following specific adversity types.

Methods: In 247 children and adolescents 8 to 16 years of age with wide variability in ELA exposure, we evaluated the hypothesis that early environments characterized by threat, but not deprivation, would be associated with accelerated development across two global biological aging metrics: DNA methylation (DNAm) age and pubertal stage relative to chronological age. We also examined whether accelerated development explained associations of ELA with depressive symptoms and externalizing problems.

Results: Exposure to threat-related ELA (e.g., violence) was associated with accelerated DNAm age and advanced pubertal stage, but exposure to deprivation (e.g., neglect, food insecurity) was not. In models including both ELA types, threat-related ELA was uniquely associated with accelerated DNAm age (β = .18) and advanced pubertal stage (β = .28), whereas deprivation was uniquely associated with delayed pubertal stage (β = -.21). Older DNAm age was related to greater depressive symptoms, and a significant indirect effect of threat exposure on depressive symptoms was observed through DNAm age.

Conclusions: Early threat-related experiences are particularly associated with accelerated biological aging in youths, which may be a mechanism linking ELA with depressive symptoms.

Keywords: DNA methylation age; Deprivation; Early life adversity; Pubertal stage; Threat; Youths.

Figure 1.

DNA methylation (DNAm) age residuals for youth as a function of the number of types of A) threat experiences and B) deprivation experiences. Scatterplots with regression lines and 95% confidence intervals, along with R-squared (R²) values, are shown. Figures 1A and 1B present unadjusted associations. Figures 1C and 1D present associations with threat and deprivation experiences residualized on covariates in the fully adjusted model (sex, race/ethnicity, family poverty status, and other dimension of early life adversity), respectively. Positive DNAm age residuals indicate accelerated DNAm age relative to chronological age.

Figure 2.

Tanner stage residuals for youth as a function of the number of types of A) threat experiences and B) deprivation experiences. Scatterplots with regression lines and 95% confidence intervals, along with R-squared (R²) values, are shown. Figures 2A and 2B present unadjusted associations. Figures 2C and 2D present associations with threat and deprivation experiences residualized on covariates in the fully adjusted model (sex, race/ethnicity, family poverty status, and other dimension of early life adversity), respectively. Positive Tanner stage residuals indicate advanced pubertal stage relative to chronological age.

Figure 3.

Indirect effect of threat exposure on depressive symptoms through DNA methylation age. Model adjusted for age, sex, race/ethnicity, and family poverty status.