Kathryn L. Humphrey, Ph.D., Ed.M.
Fellow in Child & Adolescent Depression
Ian H. Gotlib, Ph.D.
Accelerated Cellular Aging as Mechanism Linking Early Adversity with Risk for Adolescent Depression
Early adversity is associated with significantly increased risk for the development of depression. The mechanisms through which early adversity confers risk for depression, however, are not well understood. Adverse life experiences have been found to activate stress response systems, and high levels of stress have been linked to the alteration of telomeres and mitochondria. This project will allow us to examine two measures of cellular-level biomarkers of aging: (1) telomere length and (2) mitochondrial DNA copy number in a large and well-characterized sample of boys and girls. Importantly, we are collecting saliva samples in early puberty and again after the pubertal transition, which is a time of increased risk for depression in girls. We hypothesize that early adversity will accelerate the aging process, and that accelerated cellular aging, reflected through changes in telomere length and mitochondrial DNA copy number, will be linked to increases in depressive symptomatology. This longitudinal investigation will provide an important window into understanding risk for depression across development as a function of early life stress. We hope this work will elucidate the potential role of accelerated cellular aging as a pathway for vulnerability for depression, thereby facilitating the development of more effective approaches to the prevention and treatment of this debilitating disorder.