Reduced hippocampal volume in unmedicated, remitted patients with major depression versus control subjects

Background Hippocampal volumes obtained from a group of medication-free, remitted subjects with recurrent major depressive disorder (MDD) were compared against corresponding measures from healthy controls. Methods Thirty-one subjects with recurrent MDD in full remission, and 57 healthy controls underwent high resolution magnetic resonance imaging (MRI) on a GE 3T scanner. Eight patients with MDD were medication-naive, and twenty-three MDD patients were off antidepressant medications for a mean of 30 months at the time of the MRI study. Results Patients showed smaller total and posterior hippocampal volume relative to controls. Anterior hippocampal volume did not differ between patients and controls. Conclusions Recurrent depression is associated with smaller hippocampal volume which is most prominent in the posterior hippocampus. Smaller hippocampal volume appears to be a trait characteristic for MDD.