Subgenual anterior cingulate cortex in major depression: a systematic review and meta-analysis of MRI studies with...

This systematic review aims to synthesize anatomical and functional magnetic resonance imaging (MRI) findings in the subgenual anterior cingulate cortex (sgACC) and associated network among medication-free patients with major depressive disorder (MDD) compared to healthy controls.

A search for published studies was performed through Ovid (MEDLINE, Embase, APA PsycINFO) on 18 April 2024. The JBI Critical Appraisal Tools and a modified version of the specialist protocol for MRI research were used for the quality assessment. Random-effects and activation likelihood estimation (ALE) meta-analyses were applied to studies reporting numerical and stereotactic data, respectively.

Forty-two publications were reviewed. There was an equal split between the number of studies (n = 5) reporting reduced sgACC GM volume vs. no difference in MDD, with both findings supported by significant ALE clusters with peaks in the right sgACC (p ≤ .0005). Four task-based activity studies reported overactive sgACC in MDD, whereas 6 reported no difference. Both findings were supported by two significant ALE clusters with peaks in the right sgACC (p ≤ .00001). Eleven studies highlighted the global reduced resting-state network coherence of the sgACC in MDD, and reduced coherence with ventromedial prefrontal cortex (p = .00004) and right insula (p = .00002) was replicated across several reports.

Results highlight laterality and voxel-wise differences across subregions of the sgACC, displaying non-uniform GM volume, activity, and network coherence patterns in MDD. High-resolution parcellation of the sgACC should be considered in future MRI investigations.