Early-life stress and adult outcomes: Epigenetic, hormonal, and neurodevelopmental mechanisms

Abstract

Early-life stress (ELS) is a leading risk factor for mental and physical health problems in adulthood, but understanding of the underlying biological mechanisms is nascent. Using evidence from human and animal studies, this review examines three biological mechanisms (i.e., epigenetic modification, hormonal dysregulation, and altered brain development) through which ELS influences adult life. Across these studies, ELS was found to alter stress-regulating genes through epigenetic changes, disrupt cortisol regulation through the hypothalamic-pituitary-adrenal (HPA) axis, and affect the development and functioning of brain regions (e.g.,  hippocampus, prefrontal cortex, and amygdala). Rather than acting independently, these mechanisms reinforce one another in a cascade. Together, these findings demonstrate that early-life stress becomes biologically embedded in ways that persist in adulthood, highlighting the importance of early intervention and further research into whether these changes can be reversed.