Child maltreatment increases the risk of psychiatric disorders throughout childhood and into adulthood. One negative outcome of child maltreatment can be a disorder of emotional functioning, reactive attachment disorder (RAD), where the child displays wary, watchful, and emotionally withdrawn behaviors. Despite its clinical importance, little is known about the potential neurobiological consequences of RAD. Using tasks with high and low monetary rewards while undergoing functional magnetic resonance imaging, we also examined whether neural activity during reward processing was altered in children and adolescents with RAD. Significantly reduced activity in the caudate and nucleus accumbens was observed under a high monetary reward condition in the RAD group compared with the typically developed group. The striatal neural reward activity in the RAD group was markedly decreased. The present results suggest that dopaminergic dysfunction occurred in the striatum in children and adolescents with RAD, potentially leading to a future risk of psychiatric disorders such as dependence.
 We also examined gray matter alternations in RAD. The gray matter volume (GMV) was analyzed using whole-brain voxel-based morphometry. Reduced visual cortex GMV was shown in RAD children compared with control children. Visual cortex GMV of RAD children was related to their internalizing problems. The structural alternations in RAD may be due to emotional regulation impairments.
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