Life-Course Impact of Trauma on Stress Biology

This study investigates the impact of childhood adversity and elder abuse on cortisol regulation and long-term health outcomes in older adults. The objective was to assess how trauma across the life course influences hypothalamic- pituitary-adrenal (HPA) axis functioning, with cortisol patterns serving as biological markers. A systematic review methodology was applied, screening 312 published articles and identifying 75 studies that met the inclusion criteria. Results indicate that 68% of studies on childhood adversity reported significantly flatter diurnal cortisol slopes, while 61% of elder abuse studies documented elevated evening cortisol levels. Importantly, individuals with cumulative exposure to both early and late-life trauma exhibited a 35% greater reduction in cortisol variability compared to non-exposed peers, highlighting a compounded biological effect. Despite these consistent findings, 14% of included studies presented conflicting results, often due to variations in cortisol sampling protocols, self-reported adversity measures, or small sample sizes. These methodological inconsistencies represent a critical limitation, emphasising the need for standardised biomarker collection in future research. Overall, the study underscores the enduring influence of trauma on biology and provides evidence that cortisol dysregulation may serve as a measurable indicator of vulnerability to poor health outcomes in older adults.