First, the study will examine the replicability and prognostic utility of two previously identified potential biomarkers for MDD using resting state imaging. Second, investigators will conduct an exploratory, whole brain analysis combining EEG and imaging techniques to identify new potential biomarkers for MDD and treatment response as participants complete a course of TMS treatment. It is the hope to shed new light on the mechanisms underlying depression and relapse, which may allow for a more effective, personalized selection of treatment course.~Participants will complete initial screening and baseline evaluation, along with resting-state functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI) and electroencephalography (EEG) scans prior to the initial TMS treatment. Participants will complete 30-36 TMS sessions and a post-treatment evaluation, along with mid- and post-treatment fMRI, DTI and EEG scans.~It is anticipated that participants with MDD have a specific set of neural features that can classify with high precision patients with MDD from those who do not, and that align with clinical diagnoses. This set of neural features will change across the course of treatment. Further, investigators expect that improvement as rated by a common MDD measure is modulated by time of treatment.
This study is a stratified, parallel-group, single-center study utilizing multimodal imaging techniques to identify biomarkers for Major Depressive Disorder (MDD). The study goal is to identify biomarkers for MDD and treatment response that can be implemented in clinical diagnosis and care as valid and reliable measures, through monitoring neurophysiological and electrophysiological changes across the course of transcranial magnetic stimulation (TMS) treatment.