Structural brain changes in patients with recurrent major depressive disorder presenting with anxiety symptoms

Major depressive disorder (MDD) presents with extensive clinical heterogeneity. In particular, overlap with anxiety symptoms is common during depressive episodes and as a comorbid disorder. The aim of this study was to test for morphological brain differences between patients having a history of recurrent MDD with, and without, anxiety symptoms (MDD+A and MDD-A).

T1-weighted magnetic resonance images of age-, gender- and ethnically matched groups of MDD+A (n= 49) and MDD-A (n= 96) patients were available for voxel-based morphometry analysis of regional gray matter (GM) volume differences. Brain structural images were also contrasted with 183 age-, gender-, and ethnicity-matched healthy controls.

MDD+A patients had greater GM volume (P(FWE) = .002) than MDD-A patients in the right temporal cortex extending from the mid-posterior superior temporal gyrus into the posterior middle and inferior temporal gyrus. The MDD patients together showed lower GM volume than healthy controls in the superior parietal lobe.

Regional volume differences in patients are consistent with altered neuronal or glial microstructure. The temporolateral cortical differences distinguishing the 2 MDD groups suggest neurobiological differences related to the expression of anxiety symptoms in depression and provide further rationale for considering these groups independently for therapeutic outcomes studies.