Maternal and pediatric health and disease: integrating biopsychosocial models and epigenetics.

The concepts of allostasis (stability through adaptation) and accumulated life stress (McEwen's allostatic load) aim to understand childhood and adult outcomes. Chronic malnutrition, changes in social condition, and adverse early-life experiences may program phenotypes and contribute to long-lasting disease risk. However, integration of life course approaches, social and economic contexts, and comparison among different biopsychosocial models has not generally been explored. This review critically examines the literature and evaluates recent insights into how environmental stress can alter lifelong hypothalamic-pituitary-adrenal axis and immune system responsiveness and induce metabolic and neurodevelopmental maladaptation. Models of biopsychosocial stress overlap but may consider different conditions. Concepts include allostasis, which incorporates hormonal responses to predictable environmental changes, and Geronimus's "weathering," which aims to explain how socially structured, repeated stress can accumulate and increase disease vulnerability. Weathering emphasizes roles of internalized/interpersonal racism in outcomes disparities. For Mexican immigrants and Mexican Americans, the "acculturation" framework has proven especially useful to explore disparities, including preterm birth and neuropsychiatric risks in childhood. Complexities of stress assessments and recent research into epigenetic mechanisms mediating effects of physical, nutritional, psychological, and social stress are reviewed.