Maternal separation in childhood and hair cortisol concentrations in late adulthood

Background: Parent-child separation has been shown to increase the risk of a range of mental and physical health conditions later in life. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation may help to explain this association. However, few studies have examined the effect of maternal separation on cortisol in late adulthood. Methods: We examined the relationship between maternal separation in childhood and hair cortisol concentrations in late adulthood, using data from the Whitehall II study (n = 3969, mean age: 70 y, range: 60-83 y). Additionally, the role of childhood (adverse childhood experiences (ACEs), material disadvantage, and parenting), adult (marital status and social position), and health (health behaviors, cardiovascular health and medication, and depression) measures in this association were examined. Finally, we examined age of separation and reason for separation. Analysis was carried out using linear regression. Results: Hair cortisol concentrations (pg/mg) among participants who reported maternal separation during childhood were higher (B=0.179, 95% CI 0.041-0.317, p = 0.01) compared to their non-separated counterparts. This effect was robust to adjustment by childhood, adult, and health measures. Among participants who reported separation, age at onset and reason for separation were not significantly associated with hair cortisol concentrations. Conclusion: In older age individuals, hair cortisol concentrations were higher in those who reported maternal separation during childhood. This effect was independent of a wide variety of factors suggesting that there are lifelong pathways between early life separation and HPA functioning in old age.