Clinical efficacy and safety of sequential accelerated theta burst stimulation for suicidal ideation in adults with major depressive disorder: study protocol of a randomized controlled trial

Introduction: Major depressive disorder (MDD) is a prevalent psychiatric condition associated with significant suicide risk. Sequential accelerated theta-burst stimulation (aTBS), which integrates time-efficient stimulation with sequential modulation of multiple targets, represents a promising neuromodulation strategy. However, the efficacy and safety of sequential aTBS in adults with MDD and active suicidal ideation remain unexplored. This study aims to evaluate the therapeutic safety and effect of sequential aTBS on suicidal ideation in adults with MDD, and to explore its associated neurophysiological mechanisms using electroencephalography-derived P300 event-related potentials. Methods and analysis: This study is a single-blind, randomized controlled trial. Fifty-six adults with MDD will be recruited and randomly assigned (1:1) to receive either active sequential bilateral Dorsolateral Prefrontal Cortex (DLPFC) aTBS (10 weekday sessions; 3600 pulses per session) consisting of continuous theta-burst stimulation (cTBS) applied to the right DLPFC followed by intermittent theta-burst stimulation (iTBS) applied to the left DLPFC, or sham stimulation. The primary outcomes will be response and remission rates based on the 17-item Hamilton Depression Rating Scale (HAMD-17). Secondary outcomes will include the Beck Depression Inventory-II (BDI-II), the Columbia Suicide Severity Rating Scale (C-SSRS), and electroencephalography (EEG)-derived electrophysiological markers of cognitive processing (P300). Safety and tolerability will be systematically evaluated throughout the study using the Treatment Emergent Symptom Scale (TESS) to record stimulation-related adverse events. Outcome measures will be assessed at baseline, immediately after the 10-day intervention, and at 2-week and 4-week follow-ups to evaluate the short-term sustainability of treatment effects. Discussion: The results of this study will provide information regarding the efficacy and safety of sequential aTBS for MDD, evaluating its feasibility and thereby laying a foundation for future clinical interventions and scientific research. Clinical Trial Registration: https://www.medicalresearch.org.cn/index, identifier ChiCTR2500109181.