The Effects of SAINT® Neuromodulation System on Explicit and Implicit Suicidal Cognition

This multi-site, double-blind, randomized, sham-controlled mechanistic trial aims to test the effects of Magnus Neuromodulation System (MNS) with Stanford Accelerated Intermittent Neuromodulation Therapy (SAINT®) Technology on the neural circuitry of suicidal cognitions in psychiatrically hospitalized patients with Major Depressive Disorder (MDD) and active suicidal ideation (SI). This will be accomplished by applying the MNS with SAINT protocol (10 applications per day to a customized target within the left dorsolateral prefrontal cortex (L-DLPFC) identified with fMRI for five consecutive days) and measuring resting-state functional connectivity (RS FC) between the subgenual anterior cingulate cortex (sgACC) and the default mode network (DMN) at baseline and immediate-post visit. The relationship between changes in RS FC and changes in both Explicit and Implicit Suicidal Cognitions (ESC and ISC, respectively) will be determined. This study will also determine the relationship between changes in RS FC in neural networks underlying mediators of suicidal cognitions and changes in such mediators (i.e., depression, hopelessness, anhedonia) with active versus sham SAINT. The mechanistic hypothesis is that active SAINT modulates RS FC underlying ESC (sgACC-DMN) and ISC (DLPFC-ACC) and that these changes in connectivity will correlate with reductions in ESC and ISC, respectively. MDD with current Major Depressive Episode will be defined according to DSM-5 criteria, and active SI will be defined by a baseline modified Scale for Suicide Ideation (M-SSI) score ≥ 9. The primary objective is to determine if active versus sham SAINT aiTBS applied to the left dorsolateral prefrontal cortex (L-DLPFC)-subgenual anterior cingulate cortex (sgACC) is effective in modulating neural networks underlying explicit suicidal cognition (ESC) in psychiatric inpatients. The secondary objective is to determine if active versus sham SAINT aiTBS applied to the L-DLPFC-sgACC is effective in modulating neural networks underlying implicit suicidal cognition (ISC) in psychiatric inpatients. The tertiary objective is to determine if active versus sham SAINT aiTBS applied to the L-DLPFC-sgACC is effective in modulating neural networks underlying mediators of suicidal cognitions such as depression, hopelessness, and anhedonia. The study will enroll approximately 100 participants and employ a two-arm design with 50 subjects per arm. The target population is adults of all genders and ethnicities who are between 18 and 75 years of age with a diagnosis of treatment-resistant MDD experiencing a current Major Depressive Episode, with active suicidal ideation, and who are otherwise in good general health. Participants must be without contraindications to Magnetic Resonance Imaging (MRI) or transcranial magnetic stimulation (TMS) and must be able to attend all study visits. This study will deliver both active and sham SAINT via a MagPro X100 edition (MagVenture, Skovlunde, Denmark) TMS device equipped with a Cool-B65 A/P coil. The stimulation paradigm consists of 10 daily sessions (50 total over 5-days) of MNS with SAINT stimulation (3-pulse 50-Hz bursts at 5-Hz for 2-second trains, with trains every 10 seconds), delivered with 50-minute inter-session intervals (10-minute sessions, 50-minutes in between sessions). Stimulation will be delivered at 90% of the resting motor threshold (with depth correction to account for the distance between the scalp and cortex). An operator entered code (derived from the study EDC) will instruct the device to deliver active or sham magnetic stimulation.