The impact of childhood maltreatment on biological systems: Implications for clinical interventions

C hildhood maltreatment represents a significant risk factor for the development of a number of mental and physical health outcomes. Individuals who experience childhood maltreatment are at greater risk for depression, post-traumatic stress disorder (PTSD), anxiety disorders, and alcohol and drug dependence (1), as well as cardiovascular disease, gastrointestinal and metabolic disorders, and neurological, musculoskeletal and respiratory problems (2). Converging scientific evidence suggests that early adverse experiences, such as childhood maltreatment, become 'biologically embedded' into multiple systems, altering brain function, neuroendocrine responses to stress and immune system function (3,4) (Figure Collectively, these findings indicate that the root of many adult diseases originates in early childhood during sensitive periods of development when biological systems are most susceptible to adverse environmental conditions. Identification of the underlying mechanisms linking childhood maltreatment to poor health outcomes is essential to characterize vulnerability to disease, and to further our understanding and capacity to intervene early. While several recent reviews provide a broad focus on the impact of early adversity on biology, the purpose of the present review is to provide a summary of recent research specifically examining the impact of childhood maltreatment on two biological systems relevant to health outcomes -the hypothalamic-pituitary-adrenal (HPA) axis and the immune system.