Early adversity, child neglect, and stress neurobiology: From observations of impact to empirical evaluations of mechanisms

Abstract

Research on the effects of early life adversity, and in particular on the absence of responsive caregiving, has shown long‐term impacts on well‐being and development. These investigations have been conducted both in human populations and in animal models. The work has demonstrated that neglect experienced in the early years can affect not only behavior but also neurobiological functioning. In particular, studies of children in the foster care system show convergence with research on children adopted following institutional rearing in terms of dysregulation of the hypothalamic‐pituitary‐adrenal (HPA) axis, which produces the neuroendocrine hormone cortisol. The characteristic pattern that has been most commonly observed involves diminished diurnal cortisol production, particularly in terms of low levels of cortisol upon awakening. Notably, however, a number of evidence‐based interventions for infant, toddler, and preschool‐aged foster children have been shown to produce more typical patterns of cortisol production, in combination with improved behavioral, socioemotional, and foster care placement outcomes. In this paper, we review the literature on the effects of early disruptions in care on biobehavioral development, and summarize the results of the interventions for young foster children.

Maltreatment of Children With Disabilities

“…16 Neglect is associated with short-term and long-term effects on children's cognitive, socioemotional, and behavioral development. 17,18 Neglect that occurs early in life can have more profound effects on development.…”

Microglial Function in the Effects of Early-Life Stress on Brain and Behavioral Development

“…Biological embedding such as alterations in brain structure, function, connectivity, and epigenetic programming has been consistently reported in individuals exposed to adversities in childhood [2,3]. It has been suggested that exposure to ELS could modify the trajectories of brain maturation [4][5][6], increasing vulnerability to psychopathologies later in life. However, neurobiological mechanisms underlying the emergence of these changes have been poorly characterized.…”

Sex-Specific Effects of Early Life Stress on Brain Mitochondrial Function, Monoamine Levels and Neuroinflammation

“…In addition, ELS affects not only brain function and behavior, but it can lead to dysregulated neurochemical, neuroendocrine, and immune responses during adulthood. In particular, childhood abuse and parental neglect increase adult inflammatory responses and alters neuroendocrine stress responses mediated by the hypothalamic-pituitary-adrenal (HPA) axis [ 3 , 6 , 8 , 9 , 10 , 11 ]. Moreover, studies using animal models of ELS like prolonged maternal separation (MS) in rodents (in which the offspring are daily separated from their mothers before weaning) have been shown to alter adult brain monoamine levels in several brain regions related with abnormal behavior, like dopamine, serotonin, and norepinephrine [ 12 , 13 , 14 , 15 ].…”