Impact of history of esketamine treatment in the current depressive episode on response to iTBS

Introduction An increasing number of patients with treatment-resistant depression (TRD) are treated with a novel form of transcranial magnetic stimulation (TMS): the intermittent theta burst stimulation (iTBS). In this retrospective naturalistic study, we analyzed the outcome of iTBS treatment in patients with treatment-resistant depression. Objectives To investigate the impact of history of esketamine treatment in the current depressive episode on response to iTBS. Methods In this study, we included 66 hospitalized patients (57.6% female; mean age, 52.7 years) from the University Department of Psychiatry, University of Münster. Prior to iTBS treatment, 10 patients were treated with esketamine (60% female; average age, 49.8 years) and 56 were not (57% female; average age, 53.25 years). A Chi-squared test was utilized to investigate the impact of history of esketamine treatment on response to iTBS. Results The overall response rate was 51.5%. Prior to iTBS, 15% of the patients were treated with esketamine in the current episode. In the patient group with history of esketamine treatment (ESK+), 40% of the patients responded to iTBS. In the patients without history of esketamine treatment (ESK-) in the current episode, the response rate to iTBS was 53.6 %. However, history of esketamine treatment in the current episode had no significant impact on iTBS outcome (P = 0.505; χ2 = 0,626; df = 1). The difference in baseline disease severity between the groups was not statistically significant (CGI-S 6.3 (ESK+) vs 6.1 (ESK-), P = 0.281; F = 1.184; df = 64). The total rate of treatment dropouts was 3%. Conclusions History of esketamine treatment in the current episode was associated with worse outcome of iTBS. This finding was not statistically significant. iTBS may be an effective (40% response rate) and safe treatment for patients who did not respond to esketamine therapy. Disclosure of Interest M. Tonkul: None Declared, B. Baune Consultant of: Received speaker/consultation fees from AstraZeneca, Lundbeck, Pfizer, Takeda, Servier, Bristol Myers Squibb, Otsuka, LivaNova, Biogen, Angelini, and Janssen-Cilag., E. Kavakbasi Consultant of: Received speaker and advisor honoraria from LivaNova and Janssen-Cilag.