The term ‘early life stress’ has been used to describe a broad spectrum of adverse exposures during foetal life, childhood and adolescence. Early life stress and trauma are associated with a higher risk for later mental and physical health disorders, such as anxiety, depression, and post-traumatic stress disorder (P.T.S.D.) as well as cardiometabolic and inflammatory diseases and chronic pain syndromes. The objective of this brief review is to investigate the neuroendocrine responses to early life stress and their role as biological predisposing factors for later disease.Stress-related neuroendocrine alterations in response to early adversity include hyper- or hypo-activation of the stress system and may persist or worsen in later life, acting as biological vulnerability factors for the development of later disease. A key effect of stress during foetal life, childhood, and adolescence is that it programmes the developing brain, especially brain structures involved in stress reactions, such as the prefrontal cortex, the hippocampus, and the amygdala, to hyper- or hypo-react to ensuing stressors. Animal studies have shown that chronically elevated stress mediators may lead to alterations in brain development through mechanisms of accelerated loss of neurons, delays in myelination, or abnormalities in developmentally appropriate neural synaptic pruning. Critical periods of brain development represent time-windows of elevated synaptic plasticity, mediating vulnerability, or establishing resilience to stress.Stress is generally associated with acute activation of the hypothalamic-pituitary-adrenal (H.P.A.) axis and the arousal/sympathetic nervous system, as evidenced, in most studies, by elevated cortisol and catecholamine concentrations in the periphery. However, the chronic and/or intense experience of stress may be associated with chronic hyper- or hypo-activation of mediators of the stress system. This chronic condition represents dyshomeostasis, also called allostasis or cacostasis, which is related to further morbidity, such as obesity and the metabolic syndrome, diabetes mellitus type 2, atherosclerosis, osteoporosis, and immune dysfunction (Pervanidou & Chrousos, 2012).P.T.S.D., the most common stress-related disorder, is typically associated with increased secretion of corticotropin-releasing hormone centrally, with paradoxically decreased cortisol secretion peripherally, and elevated circulating catecholamine concentrations. Stress-related neuroendocrine alterations during early life might result in conditions characterized by chronic hypo-activation of the H.P.A. axis, as typically observed in P.T.S.D. and atypical depression. Scarce data exist on the longitudinal course of P.T.S.D. development and maintenance, beginning from the exposure to the traumatic event. We investigated the natural history of neuroendocrine changes in relation to P.T.S.D. development in children and adolescents experiencing a motor vehicle accident. This longitudinal study provided evidence for an initial elevation of evenin...