Impact of Psychosocial Stress in Early Life on Pace of Aging in Young Adulthood

Background: Early-life psychosocial stress is increasingly recognized as a contributor to accelerated biological aging and health disparities, yet its impact during young adulthood remains underexplored.​ Existing studies often focus on one or two dimensions of stress exposure and rely on retrospective assessments. Utilizing data from a longitudinal cohort initiated in 1989, we aim to examine the impact of early life psychosocial stress on accelerated aging in young adulthood, as well as its potential contribution to health disparities between Black and White Americans. Participants included 470 individuals (223 Black and 247 White Americans) with DNA samples collected at age > 20 years.​ Psychosocial stress exposures in the first 20 years of life were assessed prospectively using validated instruments across individual, family, and neighborhood domains. DunedinPACE, a novel biomarker of the pace of aging, was calculated from DNA methylation data generated from peripheral blood using the Illumina 450K array. The joint effect of early life psychosocial factors on DunedinPACE and the relative importance of each stressor were estimated using the Weighted Quantile Sum (WQS) approach. Mediation analysis was conducted to evaluate the contribution of early life stress to racial disparities in aging. Results: Compared to White Americans, Black Americans reported higher overall levels of early life stress (mean = 1.54 vs. 1.40, adjusted p = 0.003) and exhibited a faster pace of aging in young adulthood (DunedinPACE z-score mean = 0.21 vs. -0.19, adjusted p < 0.001). WQS analysis revealed a positive joint effect of early life psychosocial stress on DunedinPACE (β = 0.26, 95% CI: 0.167–0.353), with the top four contributors being parental socioeconomic status, peer pressure, family emotional expression, and neighborhood safety conditions. Mediation analysis indicated that early-life stress accounted for 22% of the racial disparity in biological aging (p = .01).​ Conclusion: Our findings suggest that exposure to disadvantaged psychosocial environments in early life is associated with accelerated biological aging in young adulthood. Racial differences in stress exposure partially explain disparities in aging, underscoring the importance of early interventions to reduce health disparities across the life course.