OPTIMIZING TREATMENT EFFICACY: RTMS VS. ITBS IN MAJOR DEPRESSIVE DISORDER MANAGEMENT IN TAIWAN

Abstract Background The effectiveness of the most commonly used procedures of transcranial magnetic stimulation, theta burst stimulation and high-frequency stimulation, had been discussed in the THREE-D trial and other previous research and the results revealed a non-inferiority of iTBS compared to rTMS Aims & Objectives We intend to compare the effectiveness of rTMS to that of iTBS in patients with major depressive disorder (MDD). We also want to know the different concomitant antidepressants use during the therapy defer in the outcome. Method We enrolled 64 patients with MDD diagnosed by ICD-10 between Jan 1, 2021, and Sep 30, 2023. Studied interventions included rTMS (120% RMT stimulation intensity; 10 Hz frequency; 3000 pulses per session) and iTBS (80% RMT, triplet 50 Hz bursts, repeated at 5 Hz; 1500 pulses per session), which were delivered in the left side DLPFC region. After the initial delivery of 30,000 pulses, shared decision-making processes regarding patient satisfaction and financial burden were conducted to determine whether an additional 30,000 pulses would be administered. Hamilton Depression Rating Scale (HAMD-17) were used to assess the severity of depression. The primary outcome is to compare the effectiveness of rTMS and iTBS in reduction of depression scores among patients with different pre-treatment depression severity by Mann-Whitney test. The secondary outcome is to analyze the effectiveness of rTMS and iTBS stratified by total stimulated doses by Wilcoxon signed rank test. Results The participants ranged in age from 17 to 85 years old, with the majority being female. There were no significant differences observed between the rTMS (N=37) and iTBS (N=27) groups, including gender, the number of prescribed atypical antidepressants, the number of co-medications during the research period, age, as well as pretreatment, posttreatment, and improvement scores in HAMD-17 assessments, and the total number of stimulated pulses (see Table 1).Among patients with pretreatment HAMD-17 scores equal to or higher than 17, both rTMS and iTBS resulted in significant improvements in HAMD-17 scores (p<0.001, p<0.01, respectively). However, for patients with pretreatment HAMD-17 scores lower than 17, neither rTMS nor iTBS demonstrated significant efficacy.We further stratified the participants in the rTMS and iTBS groups based on the total stimulated pulses. Participants treated with rTMS showed significant improvement in both the low dose (30000 pulses, p<0.001) and high dose (60000 pulses, p<0.001). However, significant improvement after treatment was observed only in the low dose (30000 pulses, p<0.001) and not in the high dose (60000 pulses, p=0.16) for participants treated with iTBS (see Table 2). Discussion & Conclusion Our findings highlight the inferiority of high-dose iTBS compared to high-frequency rTMS. For patients with subclinical depression, indicated by pretreatment HAMD-17 scores lower than 17, our results demonstrate no evidence of effectiveness for either brain stimulation procedure. Furthermore, if iTBS demonstrates limited efficacy for a patient after the initial 30000 pulses, it is advisable to consider transitioning to rTMS rather than administering a second set of 30000 iTBS pulses. References Blumberger DM, Vila-Rodriguez F, Thorpe KE, et al. Effectiveness of theta burst versus high-frequency repetitive transcranial magnetic stimulation in patients with depression (THREE-D): a randomised non- inferiority trial [published correction appears in Lancet. 2018 Jun 23;391(10139):e24]. Lancet. 2018;391(10131):1683-1692. doi:10.1016/S0140-6736(18)30295-2