Childhood trauma is linked to epigenetic age deceleration in young adults with previous youth residential care placements.

Background: Early adversity increases the risk for mental and physical disorders as well as premature death. Epigenetic processes, and altered epigenetic aging in particular, might mediate these effects. While the literature that examined links between early adversity and epigenetic aging is growing, results have been heterogeneous. Objective: In the current work, we explored the link between early adversity and epigenetic aging in a sample of formerly out-of-home placed young adults. Method: A total of N  = 117 young adults (32% women, age mean  = 26.3 years, SD  = 3.6 years) with previous youth residential care placements completed the Childhood Trauma Questionnaire (CTQ) and the Life Events Checklist (LEC-R) and provided blood samples for the analysis of DNA methylation using the Illumina Infinium MethylationEPIC BeadChip Microarray. Epigenetic age was estimated using Hovarth's and Hannum's epigenetic clocks. Furthermore, Hovarth's and Hannum's epigenetic age residuals were calculated as a proxy of epigenetic aging by regressing epigenetic age on chronological age. The statistical analysis plan was preregistered (https://osf.io/b9ev8). Results: Childhood trauma (CTQ) was negatively associated with Hannum's epigenetic age residuals, β  = -.23, p  = .004 when controlling for sex, BMI, smoking status and proportional white blood cell type estimates. This association was driven by experiences of physical neglect, β  = -.25, p  = .001. Lifetime trauma exposure (LEC-R) was not a significant predictor of epigenetic age residuals. Conclusion: Childhood trauma, and physical neglect in particular, was associated with decelerated epigenetic aging in our sample. More studies focusing on formerly institutionalized at-risk populations are needed to better understand which factors affect stress-related adaptations following traumatic experiences.