Inclusion Criteria:

• Primary diagnosis of unipolar major depressive disorder, in a current major depressive episode, without psychotic features
• Duration of current episode of depression ≥4 weeks and ≤3 years
• Clinical Global Impression - Severity of Illness ≥ 4
• Resistance to antidepressant treatment in a discrete illness episode
• HAMD24 Item 1 ≥ 2 and total score ≥ 20
• Subjects able to commit to protocol visit schedule
• At the end of the baseline visit, subject must have a HAMD24 score of ≥ 18 and change in score may not be ≥ 25% decrease from that seen at the screening visit

Exclusion Criteria:

• Prior TMS, vagus nerve stimulation (VNS), or electroconvulsive therapy (ECT)
• Contraindication to TMS
• Cardiac pacemakers, implanted medication pumps, intracardiac lines
• History of neurological disorder
• Unstable medical conditions
• Any psychiatric disorder, which in the judgement of the Investigator may hinder the subject in completing the procedures required by the study protocol.
• Significant acute suicide risk
• Inability to locate and quantify a motor threshold
• If sexually active female, not on an accepted method of birth control.
• Diagnoses of the following conditions (current unless otherwise stated):
  • Depression secondary to a general medical condition, or substance induced:
  • Seasonal pattern of depression as defined by Diagnostic and Statistical Manual of Mental Disorders (DSM-5)
  • Any psychotic disorder (lifetime), including history of schizophrenia, schizoaffective disorder, other psychosis, psychotic features in this or previous episodes, amnestic disorder,
  • Intellectually disabled,
  • Substance dependence or abuse within the past year (except nicotine or caffeine),
  • Bipolar disorder,
  • Obsessive compulsive disorder (lifetime),
  • Post-traumatic stress disorder (lifetime),
  • Eating disorder (lifetime).