The goal of this observational study is to demonstrate effectiveness in the treatment of Major Depressive Disorder

The primary objective is to assess the effectiveness in the treatment of Major Depressive Disorder using the CGI-I at the end of the treatment

Participants will receive 10 treatments per day for 5 days (M-F) of SAINT®

This is a prospective, multi-center, open-label study.

Up to 1000 adult subjects, in a major depressive episode, who have failed to receive satisfactory improvement from a prior antidepressant medication in the current episode, are eligible to participate in this study if they are deemed to be appropriate candidates for TMS.

Overall study duration is expected to be approximately 4 years. The study duration per subject is anticipated to be approximately 1 year.

Hypothesis: The SAINT® Neuromodulation System will demonstrate effectiveness in the treatment of MDD as measured by CGI-I at the end of the treatment (cessation of stimulation).

Inclusion Criteria:

1. Adult males or females, 18 and older, who have failed to receive satisfactory improvement from prior antidepressant medication in the current episode.
2. Confirmed primary clinical diagnosis of major depressive disorder (MDD) without psychotic features consistent with DSM-V criteria.
3. No medical conditions that would preclude the safe use of TMS.
4. Primary psychiatrist has determined TMS to be an appropriate clinical option.
5. Able to provide consent and comply with all study requirements.
6. Negative pregnancy test at the intended time of SAINT™ 5-day acute course treatment and agreement to use effective birth control during SAINT® acute therapy.

Exclusion Criteria:

1. Have any contraindication to TMS (section 2 User Manual).
2. Have any contraindication to receiving an MRI
3. Participants with an abnormal brain MRI as determined by PI, study physician or designee.
4. Deemed by the PI, study physician or designee to be a high risk of suicide or has made a suicide attempt within the last 6 months.
5. Treatment dose with cortical depth adjustment is greater than 120% motor threshold and cannot be completed.

Participants who fulfill all the inclusion criteria and none of the exclusion criteria will be enrolled into the study. Each participant will read and sign the IRB approved informed consent form prior to any screening or study procedures being performed. This open-label study involves an evaluation of the safety and effectiveness of an acute course of the SAINT® NMS.