Annual Research Review: Enduring neurobiological effects of childhood abuse and neglect

Abstract

Background and Scope Childhood maltreatment is the most important preventable cause of psychopathology accounting for about 45% of the population attributable risk for childhood onset psychiatric disorders. A key breakthrough has been the discovery that maltreatment alters trajectories of brain development. This review aims to synthesize neuroimaging findings in children who experienced caregiver neglect as well as from studies in children, adolescents and adults who experienced physical, sexual and emotional abuse. In doing so we provide preliminary answers to questions regarding the importance of type and timing of exposure, gender differences, reversibility and the relationship between brain changes and psychopathology. We also discuss whether these changes represent adaptive modifications or stress-induced damage. Findings Parental verbal abuse, witnessing domestic violence and sexual abuse appear to specifically target brain regions (auditory, visual and somatosensory cortex) and pathways that process and convey the aversive experience. Maltreatment is associated with reliable morphological alterations in anterior cingulate, dorsal lateral prefrontal and orbitofrontal cortex, corpus callosum and adult hippocampus, and with enhanced amygdala response to emotional faces and diminished striatal response to anticipated rewards. Evidence is emerging that these regions and interconnecting pathways have sensitive exposure periods when they are most vulnerable. Early deprivation and later abuse may have opposite effects on amygdala volume. Structural and functional abnormalities initially attributed to psychiatric illness may be a more direct consequence of abuse. Conclusion Childhood maltreatment exerts a prepotent influence on brain development and has been an unrecognized confound in almost all psychiatric neuroimaging studies. These brain changes may be best understood as adaptive responses to facilitate survival and reproduction in the face of adversity. Their relationship to psychopathology is complex as they are discernible in both susceptible and resilient individuals with maltreatment histories. Mechanisms fostering resilience will need to be a primary focus of future studies.

Mother nurture and the social definition of neurodevelopment

“…The evidence for the sensitive period in the Luby et al report (1) should not imply that hippocampal structure is no longer plastic beyond the preschool period, but simply that it no longer appears to reflect the influence of maternal support. Indeed, there is evidence for greater effects of childhood maltreatment on a hippocampal structure in later compared with earlier childhood (7,8), and perhaps even later for effects on the prefrontal cortex (7). A sensitive period for an environmental influence on neurodevelopment must thus be A B Fig.…”

Does sleep disruption mediate the effects of childhood maltreatment on brain structure?

“…These associations emerged from planned comparisons of regions reportedly affected by sleep loss and an exploratory analysis of regions of interest previously identified as affected by maltreatment (Teicher & Samson, 2016; Teicher et al, 2016) and corrected for multiple comparisons. Further, sleep efficiency was found to mediate the association between maltreatment and measures of whole hippocampal and hippocampal subfield volumes, and volume of inferior frontal cortex.…”

“…The most consistent findings are smaller midsagittal area or decreased fractional anisotropy of the corpus callosum and lower hippocampal volume in adults but not necessarily in youths (see Teicher and Samson, 2016; Teicher, Samson, Anderson, and Ohashi, 2016, for recent reviews). Maltreatment is also associated with attenuated development of the anterior cingulate, orbitofrontal and dorsolateral prefrontal cortex, and with enhanced amygdala response to threatening stimuli and reduced striatal response to reward (Teicher & Samson, 2016; Teicher et al, 2016). …”

Understanding gene × early adversity interactions: possibilities for insight in the biology of psychiatric disorders

“…cortex has been reported with witnessing domestic violence and thinning of the sensory cortical area for genitalia with sexual abuse [2]. These structural changes, especially the ones specific to a certain type of adversity, may be adaptive in the face of expected future adversity and seem to extend to all individuals exposed to adversity and not dependent on the development of psychopathology per se.…”

“…A series of studies have shown that exposure to adverse life events, especially when occurring in childhood, can lead to lasting biological changes that impact the function of several key systems. Brain imaging studies have reported lasting structural changes in adults exposed to childhood trauma in a number of brain regions [2]. These changes appear to be more or less specific to the type of experienced adversity.…”