Diffusion tensor imaging-based evaluation of white-matter tract alterations in schizophrenic patients with personality-related comorbidities

Background

Schizophrenia (SZ) is a complex neuropsychiatric disorder frequently accompanied by personality-related traits such as impulsivity and psychosis proneness. Emerging evidence implicates white matter (WM) dysconnectivity in the pathophysiology of SZ. This study aimed to evaluate microstructural alterations across key WM tracts using diffusion tensor imaging (DTI) and explore their associations with personality dimensions.We analyzed DTI data from 45 patients with SZ and 114 matched healthy controls from the UCLA Consortium for Neuropsychiatric Phenomics dataset. Fractional anisotropy (FA) and complementary diffusivity metrics,mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD),were extracted from 21 predefined WM tracts. Dimensional personality traits were assessed using validated psychometric instruments including the BIS-11, TCI, MPQ, and Chapman Scales. Group differences and tract-personality correlations were examined using ANCOVA and permutation-based statistics with Bonferroni correction.

Results

SZ patients showed significant reductions in FA and elevations in MD and RD in the right inferior fronto-occipital fasciculus, left optic radiation, and left posterior thalamic radiation (p < 0.05, corrected), implicating both demyelination and generalized microstructural disorganization. These abnormalities were significantly correlated with heightened impulsivity, impaired self-regulation, and increased psychosis proneness.

Conclusions

Our findings highlight distributed WM microstructural deficits in schizophrenia that extend beyond FA alterations and are linked to clinically relevant personality traits. The integration of multidimensional DTI analysis with personality profiling may enhance mechanistic understanding of psychiatric comorbidity in SZ and support future biomarker development for stratified intervention strategies.