Background: Some, although not all, studies report small hippocampal volume in patients
with major depressive disorder (MDD) relative to healthy controls. Here, we explore the
contribution of key demographic and clinical variables to this difference. Methods: We used
meta-analytic techniques to provide an updated analysis of data from 32 magnetic
resonance imaging studies of hippocampal volume in patients with MDD. Results: Our
analysis confirmed the difference in hippocampal volume, but only among patients with�…