Posterior Hippocampal Volumes Are Associated with Remission Rates in Patients with Major Depressive Disorder

Background: The hippocampus (HC) is smaller in patients with recurrent major depressive disorder (MDD), but few longitudinal studies have examined whether volume is associated with clinically meaningful outcomes such as response to treatment. Methods: We compared regional (head and body/tail) HC volumes in 46 patients with MDD, 14 of whom remitted after 8 weeks of first treatment to HC volumes of 32 patients who were not in remission after 8 weeks. Results: Patients who remitted had larger pretreatment hippocampal body/tail volumes bilaterally compared with those who were not in remission at 8 weeks. This difference was not apparent in either the right or left hippocampal head. Conclusions: These findings extend a small number of previous reports, suggesting that regional brain volumes might be associated with rate and extent of clinical response to antidepressant medication.