Microstructural Disruption of the Forceps Minor in Schizophrenia: A Potential Clinical Imaging Biomarker Using Translational DTI

Schizophrenia is one of the most complex brain disorders, arising from multidimensional pathophysiological processes that span genetic vulnerability, neurotransmitter dysregulation, structural brain damage, and large-scale brain network dysfunction. Large-scale neuroimaging studies have consistently demonstrated the critical role of frontal brain regions in schizophrenia. Despite substantial progress, the precise localization of structural damage within these regions and the neurobiological mechanisms linking such alterations to disease pathology remain poorly understood. In this study, we included a total of 115 subjects from two sites of the B-SNIP dataset, comprising 60 healthy controls and 55 individuals with schizophrenia. We employed diffusion tensor imaging (DTI) to precisely characterize specific structural alterations in the frontal brain regions associated with schizophrenia. Our findings reveal significant microstructural abnormalities in the forceps minor, a major commissural white-matter tract that serves as a critical interhemispheric bridge between the bilateral frontal lobes. Network-level mapping further demonstrates that the forceps minor is closely integrated with large-scale brain networks, particularly the default mode network, and maintains strong structural connectivity with orbitofrontal regions-both of which are known to exhibit dysfunction in schizophrenia. Moreover, converging evidence suggests that the forceps minor plays an important role in the regulation of social behavior, a core domain of impairment in schizophrenia. Collectively, these findings identify the forceps minor as a promising structural imaging biomarker for schizophrenia and provide novel insights into the microstructural mechanisms underlying the disorder.