Eight‐week antidepressant treatment reduces functional connectivity in first‐episode drug‐naïve patients with major depressive disorder

FIGURE 1. Eight‐week antidepressant treatment decreases edge‐based FC in MDD patients (n = 40). The brain maps show the affected edges (lines) and their connecting nodes (spheres) from several perspectives. The size of a node indicates how many affected edges are connected to this sphere. Bigger nodes have more affected edges than smaller ones. The color of a node indicates which network it belongs to. The color of edges (blue) indicates that the FC is decreased in MDD patients after treatment. A, anterior; DAN, dorsal attention network; DMN, default mode network; FC, functional connectivity; FPN, frontoparietal network; L, left; P, posterior; R, right; SCN, subcortical network; SMN, somatosensory network; VAN, ventral attention network; VN, visual network

FIGURE 2. Antidepressant effect and group difference in edge‐based FC. Heatmaps show the number of significant edges for each pair of networks for each of the three contrasts: (a) 8‐week versus baseline of treatment in MDD (n = 40); (b) MDD at baseline versus HCs (n = 40 vs. n = 85); (c) MDD after treatment versus HCs (n = 40 vs. n = 85). HCs, healthy controls; MDD, patients with major depressive disorder. For network abbreviation, please refer to the legend of Figure 1

FIGURE 3. Eight‐week antidepressant treatment decreases large‐scale network FC in MDD patients (n = 40). (a) The upper‐left heatmap shows the T values of paired‐sample T tests on FC for each pair of networks between 8‐week treatment and baseline. For T value color bar, blue indicates FC decrease while red indicates FC increase after treatment. The schematic diagram on the upper‐right panel shows the network connections with significant FC decrease for the seven networks after treatment. The bottom heatmaps show the mean FC for each pair of networks in MDD patients (b) at baseline and (c) after treatment. The color bar indicates FC value. FC, functional connectivity; MDD, patients with major depressive disorder. For network abbreviations, please refer to the legend of Figure 1. *FDR‐corrected p < .05 (two‐tailed)

FIGURE 4. Indifference of large‐scale network FC between MDD patients and healthy controls. The heatmaps show T values of two‐sample T tests on FC (a) between MDD at baseline with HCs (n = 40 vs. n = 85), and (b) between MDD after treatment with HCs (n = 40 vs. n = 85), for all pairs of networks. For the T value color bar, blue indicates FC decrease while red indicates FC increase in MDD as compared to HCs. HCs, healthy controls; MDD, patients with major depressive disorder. For network abbreviations, please refer to the legend of Figure 1