rTMS Treatment for Major Depressive Disorder

Inclusion Criteria for healthy participants: * 18-65 years of age * Capacity to provide informed consent form to participate in the study Inclusion Criteria for participants with Major Depressive Disorder (MDD): * 18-65 years of age * Capacity to provide informed consent form to participate in the study * Currently in a major depressive episode. Comorbid anxiety disorders and personality disorders will be allowed provided that MDD is the primary diagnosis. Exclusion Criteria for all participants: * Meeting criteria, in the past or currently, for bipolar affective disorder, hypomania or mania. * Meeting criteria, in the past or currently, for a primary psychotic disorder (e.g., schizophrenia). * Neurological conditions with known structural brain lesions, e.g., intracranial masses, multiple sclerosis. * Any personal history of seizures or a family history of epilepsy in a first-degree relative. * Metal in the body that is ferromagnetic or metallic injury to the eyes. * Implanted pacemakers, medication pumps, vagal stimulators, deep brain stimulators, or ventriculoperitoneal shunts, etc. * Substance abuse or dependence that is current and active within the last six months, as indicated by self-report (e.g., heroin, cocaine, methamphetamines). * Inability to meet the safety criteria for MRI scanning for any other reason. * Severe or unstable medical illness. * Currently pregnant, as assessed with urine pregnancy test in women of childbearing age.