Evans JW, et al. - Researchers used functional magnetic resonance imaging (fMRI) to assess the effect of a single ketamine infusion on the resting state default mode network (DMN) at two and 10 days after a single ketamine infusion in unmedicated major depressive disorder (MDD) subjects as well as healthy controls (HCs). Findings revealed connectivity changes in the insula in MDD subjects, thereby indicating that ketamine could normalize the interaction between the DMN and salience networks, supporting the triple network dysfunction model of MDD.