Neurobiology of early life stress: clinical studies

A burgeoning number of clinical studies have evaluated the immediate and long-term neurobiological effects of early developmental stress, eg, child abuse and neglect or parental loss, in the past years. This review summarizes and discusses the available findings from neuroendocrine (hypothalamic-pituitary-adrenal axis, other neuroendocrine axes), neurochemical (catecholamines, serotonin, other neurotransmitters), psychophysiological (autonomic function, startle reactivity, brain electrical activity) and neuroimaging studies (brain structure, function) conducted in children or adults with a history of early life stress, with or without psychiatric disorders. Early developmental stress in humans appears to be associated with neurobiological alterations that are similar to many findings in animal models of early life stress, and likely represent the biological basis of an enhanced risk for psychopathology. Clinical studies are now beginning to explore potentially differential neurobiological effects of different types of early life stress and the existence of critical developmental periods, which may be sensitive to the neurobiological effects of specific stressors. In addition, the role of a multitude of moderating and mediating factors in the determination of individual vulnerability or resilience to the neurobiological effects of early life stress should be addressed. Findings from such studies may ultimately help to prevent the deleterious neurobiological and psychopathological consequences in the unacceptably high number of children exposed to early life stress in modern society.