Childhood Adversity and Neural Development: A Systematic Review.

An extensive literature on childhood adversity and neurodevelopment has emerged over the past decade. We evaluate two conceptual models of adversity and neurodevelopment-the dimensional model of adversity and stress acceleration model-in a systematic review of 109 studies using MRI-based measures of neural structure and function in children and adolescents. Consistent with the dimensional model, children exposed to threat had reduced amygdala, medial prefrontal cortex (mPFC), and hippocampal volume and heightened amygdala activation to threat in a majority of studies; these patterns were not observed consistently in children exposed to deprivation. In contrast, reduced volume and altered function in frontoparietal regions were observed consistently in children exposed to deprivation but not children exposed to threat. Evidence for accelerated development in amygdala-mPFC circuits was limited but emerged in other metrics of neurodevelopment. Progress in charting neurodevelopmental consequences of adversity requires larger samples, longitudinal designs, and more precise assessments of adversity.