The nearest centroid classification analysis identified six edges in the alpha band that best characterized the depressed state. Five of these edges involved a hub node, with higher coherence values in the MDD group: three of these edges connected pairs of nodes between the left and right frontopolar and DLPFC regions (Af1-Fz and Fp2-Fpz, Af1-Fpz and Af2-Fpz, and Fp1-Af1 and Fp2-Fpz), one connected a pair between the left frontopolar and DLPFC regions (Fp1-Fpz and Af1-Fpz), and one a pair between the right frontopolar and right temporal regions (Fp2-Fpz and T4-Fc6). The sixth edge connected a pair of nodes in the right parietooccipital region which were not hub nodes, and for which coherence was lower in the MDD group than controls (Po2-Pz and O2-Oz). Supervised hierarchical clustering (Figure 6) shows that MDD cases (shown in black in the top color bar) tend to cluster together, indicating that the combinations of these edges discriminate cases from controls. The cluster tree on the left side shows the relationship among the edges. The bottom five edges (indicated by green in the left color bar)
