Two major clinically relevant findings stimulated us to conduct these studies: the identification of Wfs1 as a gene that can be causative for MDD (Flint and Kendler, 2014); and the dynamic structural alterations to dendritic arbors of superficial layer pyramidal cells that have been documented in human postmortem and animal studies in response to stress (Rajkowska et al., 1999; Radley et al., 2004). Here, WFS1 is linked to major depressive disorder.