Biological Embedding of Child Maltreatment Through Inflammation

Abstract

Early-life stress and traumas such as childhood maltreatment are well-known risk factors for the development of subsequent psychopathology. However, little is known about the biological mechanisms through which childhood exposure to traumatic stress contributes to the development of psychopathology. In this chapter, we propose that the immune system, specifically the inflammatory response, may be one of the key mediating pathways that account for the effects of childhood exposure to traumatic stress on the development of psychopathology. This chapter focuses specifically on the stress associated with childhood maltreatment and the outcome of depression to illustrate the mechanistic role of inflammation. Molecular theories suggest that inflammatory cytokines released during systemic inflammatory responses can interfere with brain functioning in ways that contribute to depression pathophysiology over time. Epidemiological and experimental studies in humans provide robust evidence for the association between inflammation and depression. Acute and chronic psychosocial stress akin to maltreatment can trigger inflammatory responses similar to bodily responses to physical injury. Evidence from the population-based life-course study, the Dunedin Multidisciplinary Health and Development Study, reveals elevated inflammatory response among individuals with a history of childhood maltreatment; childhood maltreatment, in turn, contributes to identifying subtypes of recurrent and persistent depression characterized by accompanying elevation in inflammation levels. Further research is needed to characterize the links between childhood traumatic stress, inflammation, and psychopathology, and to investigate the potential effects of anti-inflammatory interventions on treatment-resistant depression. Identification of biological pathways may uncover new targets for prevention and treatment of childhood stress-related psychopathology.