bioRxiv [Preprint]. 2026 Mar 31:2026.03.28.714565. doi: 10.64898/2026.03.28.714565. ABSTRACT BACKGROUND: Large-scale T1-weighted MRI studies have established grey-matter abnormalities in bipolar disorder (BD), with our group contributing to consensus findings. However, structural connectivity, particularly within emotion- and reward-related circuits, remains poorly understood. Diffusion-weighted MRI (dMRI) enables investigation of white-matter pathways, yet prior work is constrained by small samples, methodological heterogeneity, and unclear medication effects. We conducted the largest dMRI network analysis in BD, relating symptom burden and polypharmacy to tractography-derived connectivity and graph-theoretic metrics. METHODS: Cross-sectional structural and diffusion MRI scans from 449 individuals with BD (35.7±12.6 years) and 510 […]
