Clinical Research Directory

Inclusion Criteria: * Men or women aged 18 to 55 years of age * Mini-International Neuropsychiatric Interview-confirmed diagnosis of MDD, as a single or recurring episode * Symptoms of MDD have not improved after ≥ 1 but ≤ 7 adequate dose(s) of antidepressant trial(s) in the current depressive episode * A baseline score of ≥ 15 on the 17-item Hamilton Rating Scale for Depression (HRSD-17) * Have received a stable antidepressant regimen for at least four weeks prior to entering trial * Are voluntary and competent to consent to study * Can speak and read English Exclusion Criteria: * Current or past (\< 3 months) substance (including nicotine) or alcohol abuse/dependence, as defined in DSM-5 criteria * Positive urine test for illegal substances, cannabis, or cotinine * Suicide attempt in the past three months and/or active suicidal intent * Pregnancy (confirmed by urine test) and/or lactation * Psychotic features in the current episode * Any comorbid mental health disorders (including, but not limited to lifetime history of psychotic disorders, OCD, PTSD and/or bipolar I or II disorder) with the exception of anxiety/panic disorders and ADHD * Significant unstable medical or neurologic illness confirmed by medical history and blood test at baseline (e.g. uncontrolled diabetes, or renal dysfunction) * Organic cause to the depressive symptoms (e.g. thyroid dysfunctions), as ruled out by the referring physician * Contraindication for TMS (e.g., personal history of epilepsy or convulsion, metallic head implant, pacemaker) * Contraindication for MRI (e.g. metallic implant, claustrophobia) * Have undergone a prior PET or SPECT research study * ECT or rTMS treatment in the current depressive episode * Benzodiazepine use * Have a body mass index (BMI) higher then 35 or lower then 18 * Any other condition that, in the opinion of the investigators, would adversely affect the participant's ability to complete the study