Hippocampal volume in relation to clinical and cognitive outcome after electroconvulsive therapy in depression

Objective In a previous magnetic resonance imaging (MRI) study, we found a significant increase in hippocampal volume immediately after electroconvulsive therapy (ECT) in patients with depression. The aim of this study was to evaluate hippocampal volume up to 1year after ECT and investigate its possible relation to clinical and cognitive outcome. Method Clinical and cognitive outcome in 12 in-patients with depression receiving antidepressive pharmacological treatment referred for ECT were investigated with the Montgomery-Asberg Depression Rating Scale (MADRS) and a broad neuropsychological test battery within 1week before and after ECT. The assessments were repeated 6 and 12months after baseline in 10 and seven of these patients, respectively. Hippocampal volumes were measured on all four occasions with 3Tesla MRI. Results Hippocampal volume returned to baseline during the follow-up period of 6months. Neither the significant antidepressant effect nor the significant transient decrease in executive and verbal episodic memory tests after ECT could be related to changes in hippocampal volume. No persistent cognitive side effects were observed 1year after ECT. Conclusion The immediate increase in hippocampal volume after ECT is reversible and is not related to clinical or cognitive outcome.