Inclusion Criteria:  Veterans participating in the VA TMS Pilot Program age 18 years or older Able to provide written informed consent to participate in the EEG portion of this study and to allow linking such data to data collected as part of the TMS Pilot Program Diagnosis of MDD based on DSM-5 criteria and be currently depressed despite prior treatment with at least one adequate antidepressant treatment Receiving stable doses of psychiatric medications (no dose changes for >4 weeks prior to study entry), in stable psychotherapy, or receiving no psychiatric medications and/or psychotherapy  Exclusion Criteria:  History of seizure disorder Known structural or neurologic abnormalities present or close to the treatment site that would increase risk of seizure History of brain surgery History of recent traumatic brain injury (within 6 months) or any history of moderate to severe traumatic brain injury Clinical evidence of severe or uncontrolled alcohol or substance use disorders within three months Active withdrawal from alcohol or other substances of abuse Implanted metal device in the head that would increase the risk of TMS Metal in the head that would increase the risk of TMS Current psychosis