Brain Connectivity in Depression

This study originally included 140 subjects with medication-refractory depression undergoing 10 Hz transcranial magnetic stimulation (10Hz-TMS) to the left dorsal lateral prefrontal cortex (DLPFC), with the goal of having 60 completers with good quality data. Subjects were recruited from the TMS clinics at Beth Israel Deaconess Medical Center, Brigham \& Women's Hospital, and Butler Hospital. Subjects underwent an hour-long MRI scanning session, an optional DNA-sample collection, up to three 20 minute neuronavigation sessions for marking the site of TMS stimulation, questionnaires, and a behavioral testing battery before and after their TMS treatment course. The task battery included the Emotion Conflict Resolution (ECR) task, Multi-Source Interference Task (MSIT), War Game (Gambling) task, and Associative Learning with Reversal task. Subjects' scores on the Quick Inventory of Depressive Symptomatology (QIDS) and Beck Depression Inventory (BDI) were assessed before and after the TMS course. MRI data was utilized to identify brain regions whose connectivity to the stimulation site co-varies with the aforementioned measures of symptom improvement. This was the only study group until August 30, 2022, and the primary outcome was analyzed for the 10Hz-TMS group. Due to changes in clinical standard of care from 10Hz-TMS to a newer version of TMS termed intermittent theta burst (iTBS), in September 2022 a second group was added to include patients receiving this new form of TMS. This second group included another 100 patients with medication-refractory depression undergoing iTBS to the left dorsal lateral prefrontal cortex (DLPFC), with the intent to have 80 completers. Massachusetts General Hospital was added as a data collection site in lieu of Butler Hospital. Subjects will undergo an hour-long MRI scanning session, up to three 20 minute neuronavigation sessions for marking the site of TMS stimulation, questionnaires, and a behavioral testing battery before and after their TMS treatment course. The task battery will included the Emotion Conflict Resolution (ECR) task, Multi-Source Interference Task (MSIT), Penn Emotion Recognition Test, the Suicide/Death Implicit Association Test, and Associative Learning with Reversal task. Subjects' scores on the Beck Depression Inventory (BDI) were assessed before and after the TMS course. MRI data will be utilized to identify brain regions whose connectivity to the stimulation site co-varies with the aforementioned measures of symptom improvement. Due to a higher dropout rate than anticipated, in March of 2025 an amendment was added to include an additional 20 subjects in the second group's enrollment goal to increase the likelihood of achieving 80 completers.