Cover legend: Brain regions (“nodes,” colored circles) that exhibited significant differences in nodal efficiency among remitted geriatric depression (RGD) patients, amnestic mild cognitive impairment (aMCI) patients, and controls. Brown lines represent t he backbone of white-matter structural networks in healthy subjects determined using diffusion tensor imaging and deterministic tractography. The nodal efficiency for a given node measures the average shortest path length between the node and all of the other nodes in the network. The nodes in blue (mainly in the frontal cortex) exhibited reduced efficiency in aMCI and RGD patients relative to controls. The node in green (in the prefrontal cortex) showed reduced efficiency in RGD patients relative to aMCI patients. The node in yellow (in the inferior frontal gyrus) showed reduced efficiency in aMCI patients relative to the RGD patients. For more information, see the article by Bai et al. (pages 4307–4318).