Longitudinal diffusion weighted imaging of limbic regions in patients with major depressive disorder after 6 years and partial to full remission.

•Both MDD patients and HCs showed reduced FA in the regions of interest, indicative of tract integrity reduction, at the 6-year follow-up scan.•There was a significant effect of MDD diagnosis on longitudinal FA of the left dorsal cingulum and left parahippocampal cingulum.•The reduction of left rostral cingulum and right uncinate fasciculus FA were inversely related to HAM-D improvement within the MDD group.