Stress during the first 1,000 days of life in humans, when everything begins

Brain development from fetal life to early childhood occurs in highly sensitive periods, during which stress exposure—adaptive or toxic, prenatal or postnatal—can shape neural circuits involved in emotional regulation, particularly amygdala-centered networks. This review synthesizes current evidence on the biological mechanisms of early-life stress and protective interventions. It is based on a narrative review integrating original research, review articles, and international guidelines selected