Serum Brain-derived Neurotrophic Factor Levels Following Electroconvulsive Therapy in Treatment-resistant Depressed Patients

Objectives: To determine whether serum levels of brain-derived neurotrophic factor (BDNF) are associated with response to electroconvulsive therapy (ECT) in treatment-resistant depressed patients with a relatively lon‐ ger period of measurement. Methods: This study included 30 Japanese unipolar depressed patients with current major depressive episode. Montgomery-Äsberg Depression Rating Scale (MADRS) score was ≥21 in all subjects. ECT was performed twice a week for a total of 4–10 sessions. Serum BDNF levels were measured before ECT (T0), the day after the last ECT session (T1), and 1 month after the last ECT session (T2). Patient response to treatment was de‐ fined as a ≥50% decrease compared with the pretreatment total MADRS score. Results: Serum BDNF levels showed no significant variation among the patients during the entire study period. In responders, serum BDNF levels showed a progressive increase, and the differences between T0 and T1 and between T0 and T2 were significant (p=0.022 and p=0.007, respectively). In non-responders, serum BDNF lev‐ els showed a progressive decrease, and the difference between T0 and T2 was significant (p=0.012). No signifi‐ cant association was identified between change in serum BDNF level and change in total MADRS score in any of the patients following ECT. Conclusions: The present results showed that serum BDNF levels after ECT increased progressively in res‐ ponders, but not in non-responders. Our results provide important information for understanding the exact role of BDNF in the antidepressive effects of ECT.