RecruitingDevice studyCortical Inhibition as a Biomarker of Response in a Comparison of Bilateral Versus Unilateral Accelerated Theta Burst Stimulation for Suicidal Ideation in Treatment-Resistant Depression -COMBAT-SIThis is a prospective clinical trial to confirm the effectiveness of bilateral accelerated theta burst stimulation (aTBS) on suicidal ideation (SI), while exploring cortical inhibition measures in this treatment paradigm. In this proposed study, the investigators will evaluate the anti-suicidal effects of bilateral aTBS over the DLPFC compared to accelerated intermittent theta burst stimulation (aiTBS) over the left DLPFC in participants with TRD and SI. Additionally, the investigators aim to identify neurophysiological targets through which bilateral aTBS induces remission of SI in TRD differentially from aiTBS.