A number of nodes were identified as hub nodes that had significantly different degree DN (i.e., average coherence with all other nodes) between the MDD group and normal controls (Table 2). Two frontopolar hub nodes, Fp1-Fpz and Fp2-Fpz, met the Bonferroni threshold for significance in each of the four frequency bands. In the theta and alpha band, these same nodes plus two DLPFC nodes, Af1-Fpz and Af2-Fpz, had significantly higher degree DN in subjects with MDD. These four nodes showed broadly higher connectivity CE in the alpha band with all brain regions in MDD subjects compared with healthy controls. In the beta band, these same four plus 21 additional hub nodes showed greater connectivity in MDD than in controls. Across all four frequency bands, no hub node had higher connectivity in controls than in MDD subjects. Maps showing the median connectivity CE between one of these nodes, Fp1-Fpz, and all other nodes in all frequency bands for MDD and control subjects separately are presented in Figure 5.
