Divergent effects of sex on structural covariance networks of thalamic nuclei in drug-naive patients with major depressive disorder

Motivation: Major depressive disorder (MDD) shows sex differences in terms of incidence and symptoms, but the neurobiological basis underlying these sex differences remains to be clarified. Goal(s): To investigate sex differences in MDD and HC, focusing on the structural covariance networks (SCN) of thalamic nuclei. Approach: We segmented thalamic nuclei and constructed a SCN using 3D T1 and DTI. Results: SCN analysis in MDD patients showed reduced nodal degree in the right LGN and left LP nuclei in females. Betweenness centrality was lower in the left MV (Re), VA, and right VAmc, while both betweenness and closeness centrality increased in the right PuL. Impact: The study highlights thalamic nuclei changes in MDD, revealing intrinsic thalamic nodal network alterations in females. Structural covariation pattern between thalamic nuclei may be an important marker of sex severity in MDD.