• Inpatients or outpatients

• Voluntary clinical patient with the capacity to assent to treatment and a parent or legal guardian with the capacity to consent

• Female or male

• 12-18 years of age

• Diagnosed with MDD based on Diagnostic and Statistical Manual for Mental Disorders, 5th edition (DSM-5) criteria122 with the Mini-International Neuropsychiatric Interview for Children and Adolescents (MINI Kid) in subjects 12-17 years of age;118 The Mini-International Neuropsychiatric Interview will be used for subjects who are 18 years of age117

• In a current episode of MDD with duration of at least 4 weeks but less than 3 years

• Depressive symptom severity as demonstrated by CDRS-R total composite score of 40 or greater and a suicidal ideation score of 3 or more on item 13 of the CDRS-R109

• Demonstrating that depressive symptom severity as evaluated at the screening visit does not improve between screening and baseline by 25% or more

• Eligible for transcranial magnetic stimulation (TMS) based on safety criteria104

• On a medically acceptable form of birth control if female

• Taking an antidepressant medication if recommended by the referring clinician and agreed upon by parents and patients. Please note that patients are not required to take an antidepressant medication for study participation for practical, ethical, and human subject protection concerns. Medication status and prior treatment resistance will be carefully recorded with the Antidepressant Treatment History Form113 criteria for relevant statistical considerations.