Response to Intermittent Theta Burst Stimulation in Treatment-Resistant Depression

INTRODUCTION: Intermittent theta burst stimulation (iTBS) is a novel form of repetitive transcranial magnetic stimulation (rTMS) conducted in patients with treatment-resistant depression (TRD). In this retrospective naturalistic study, we investigated the outcome of iTBS in treatment-resistant depression patients with (ECT+) and without (ECT-) history of electroconvulsive therapy (ECT) in their current depressive episode, as well as among previous ECT responders and nonresponders. METHODS: We included 66 inpatients (57.6% women; mean age, 52.7 years) at a German University Department of Psychiatry. A binary logistic regression model was utilized to investigate the impact of ECT treatment history on response to iTBS. RESULTS: Overall response rate was 51.5%. History of ECT in the current episode was present in 47% of patients. In the regression model, history of ECT in the current episode was associated with significantly worse response to iTBS (odds ratio, 0.252; 95% confidence interval, 0.085-0.743; P = 0.013), whereas other disease- and treatment-related covariates had no significant impact on treatment outcome. In the ECT+ group, ECT nonresponders showed a significantly worse outcome of iTBS than ECT responders. Overall rate of treatment discontinuations was 3%. CONCLUSIONS: In this study, iTBS was most effective in patients without history of ECT in the current episode. Previous ECT responders had better outcome following iTBS than ECT nonresponders. Hence, patients with ECT response, who had to discontinue ECT due to side effects or complications, may be considered suitable candidates to be switched to iTBS.