Altered white matter integrity in young adults with first-episode, treatment-naive, and treatment-responsive depression

Abnormalities of the white matter (WM) tracts integrity in brain areas involved in emotional regulation have been postulated in major depressive disorder (MDD). However, there is no diffusion tensor imaging (DTI) study in patients with treatment-responsive MDD at present. DTI scans were performed on 22 patients with treatment-responsive MDD and 19 well-matched healthy subjects. Tract-based spatial statistics (TBSS) approach was employed to analyze the scans. Voxel-wise statistics revealed four brain WM tracts with lower fractional anisotropy (FA) in patients compared to healthy subjects: the bilateral internal capsule, the genu of corpus callosum, the bilateral anterior corona radiata, and the right external capsule. FA values were nowhere higher in patients compared to healthy subjects. Our findings demonstrate that the abnormalities of the WM tracts, major in the projection fibers and corpus callosum, may contribute to the pathogenesis of treatment-responsive MDD.

► MDD may exhibit abnormalities of WM integrity in regions associated with emotional regulation.
► The patients enrolled in the present study were treatment-responsive young adults.
► TBSS method could detect WM tracts integrity alterations in patients and controls.
► Alterations of projection fibers and corpus callosum integrity attribute to pathogenesis of MDD.