Subcortical regional volume vulnerability linked to child neglect without other forms of maltreatment

Child neglect during critical stages of development has been associated with long-term adverse outcomes, including impairments in social, emotional, and physical health, as well as elevated risks of mental and cardiovascular disorders. This study examined whether alterations in corpus callosum (CC) morphology—essential for interhemispheric communication—are associated with the neural mechanisms underlying psychosocial characteristics in children exposed to neglect. Brain morphology was assessed using T1-weighted magnetic resonance imaging in Japanese children with a history of neglect (neglect group, n = 22) and compared with non-maltreated Japanese children (non-CM group, n = 66). Boys in the neglect group exhibited a greater volume in the middle anterior portion of the CC (CC2) than non-CM boys ( d = 0.81, estimate = 208.38, t = 3.35, false discovery rate [FDR]-adjusted p = 0.01). Additionally, CC2 volume was positively correlated with hyperactivity-inattention scores across both sexes ( d = 0.53, estimate = 111.68, t = 2.85, FDR-adjusted p = 0.03). These findings indicate sex-specific effects of neglect on CC development and emphasize the importance of clarifying the neurodevelopmental consequences of neglect and their associations with psychosocial functioning. • Altered brain development was linked to early-life neglect. • Neglect-exposed boys exhibited greater corpus callosum (CC2) volume. • CC2 volume was positively correlated with hyperactivity–inattention scores. • CC2 volume may serve as a biomarker for behavioral symptoms in neglected children. • Sex differences were observed in brain responses to early adverse experiences.