53. The Anterior Hippocampus and the Pathogenesis of Major Depression

The hippocampus is implicated in the pathogenesis of major depressive disorder (MDD). The hippocampus differs functionally along its longitudinal axis, the anterior being involved with stress processing and mood, and posterior with visuo-spatial navigation. Neurogenesis is impaired in anterior hippocampus in primate and rodent models of depression and in postmortem studies of unmedicated MDD compared with healthy volunteers (HV) and medicated MDD. Functioning along the anterior-posterior axis has not been examined in MDD in vivo. In this study, we examine anterior hippocampal functioning using functional magnetic resonance imaging (fMRI) with an emotional pattern separation task (E-MST).