Fig. 4: Summary of brain networks and regions most frequently associated with depressive symptoms in SSDs, based on 19 studies with fMRI.

The color scale corresponds to the frequency of the region or network reported. A A schematic illustration of regions implicated in depressive symptoms in SSDs. Subcortical regions are shown through a glass brain, and cortical regions are displayed on the cerebral cortex, as per the Surface-Based Multimodal parcellation. Top regions include the left caudate and putamen and bilateral frontal area. Note that some studies investigated specific regions of interest (ROIs), and did not use a whole-brain approach. Implicated regions are further subdivided into positive (B) and negative (C) associations with depressive symptoms. D A schematic illustration of networks implicated in depressive symptoms in SSDs. Networks are displayed on the cerebral cortex, as per the Cole-Anticevic Brain-wide Network Partition, AUD Auditory Network, DMN Default Mode Network, FPN Frontoparietal Network, LAN Language Network, SMN Somatomotor Network, SN Salience Network. Networks were reported bilaterally but are displayed on the left hemisphere for clarity. Top network connections include within- DMN, FPN, and SN. All studies found negative correlations between network-based functional connectivity and depressive symptoms. One study identified both negative and positive associations with depressive symptoms (positive association found within-FPN, and between DMN-SMN).