SAINT for MDD in an Inpatient Setting Follow-on

Inclusion Criteria: 1. Adults of all genders between the ages of 18 and 75 years at the time of screening, who have failed to receive satisfactory improvement from prior antidepressant medication in the current episode 2. Concurrently enrolled in the NIH multi-site trial titled "The Effects of SAINT® Neuromodulation System on Explicit and Implicit Suicidal Cognition" 3. Able to read, understand, and provide written, dated informed consent prior to screening. Proficiency in English sufficient to complete questionnaires/follow instructions during fMRI assessments and SAINT treatments 4. Stated willingness to comply with all study procedures including availability for the duration of the study and to communicate with study personnel about adverse events and other clinically important information 5. Currently diagnosed with Major Depressive Disorder (MDD) and meets criteria for a current Major Depressive Episode (MDE) according to the criteria defined in the Diagnosis and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5) 6. Medical records confirming a history of moderate to severe treatment- resistance as defined by a score of 7-14 on the Maudsley Staging Method153 (MSM) 7. Endorses clinically significant explicit suicidal cognitions (score ≥ 9 on the M-SSI and score ≥ 6 on the BSS self-report) 8. MADRS score of ≥20 at screening (visit 1) 9. rTMS/iTBS naive 10. Access to ongoing psychiatric care before and after completion of the study 11. Access to clinical rTMS after hospital discharge 12. In good general health, as evidenced by medical history 13. For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation. Must have a negative urine pregnancy test prior to enrollment Exclusion Criteria: 1. Pregnancy as confirmed by a positive urine pregnancy test 2. The presence or diagnosis of a prominent anxiety disorder, personality disorder, or dysthymia which in the Investigator's opinion is predominant to MDD 3. Depressed mood/dysphoria as a result of an illness other than MDD (e.g. gender dysphoria) 4. Current severe insomnia (must sleep a minimum of 5 hours each night before stimulation) 5. Current mania or psychosis 6. A history of Bipolar Affective Disorder or Primary Psychotic Disorder 7. Autism Spectrum disorder or Intellectual Disability 8. A diagnosis of obsessive-compulsive disorder (OCD) 9. Current moderate or severe substance use disorder or demonstrating signs of acute substance withdrawal 10. Urine screening test positive for illicit substances 11. Any history of ECT (greater than 8 sessions) without meeting responder criteria 12. Recent (during the current depressive episode) or concurrent use of a rapid acting antidepressant agent (i.e., ketamine or a course of ECT) 13. History of significant neurologic disease, including dementia, Parkinson's or Huntington's disease, brain tumor, unexpected seizure/epilepsy disorder, subdural hematoma, multiple sclerosis, or history of significant head trauma 14. Untreated or insufficiently treated endocrine disorder 15. Contraindications to receiving rTMS (e.g., metal in head, history of seizure, known brain lesion) 16. Contraindications to MRI (ferromagnetic metal in their body) 17. Any current or past history of any physical condition which, in the investigator's opinion, might put the subject at risk or interfere with study results interpretation 18. Treatment with another investigational drug or other intervention within the study period 19. Depth-adjusted SAINT® treatment dose \> 65% maximum stimulator output (MSO) 20. Any other condition deemed by the PI to interfere with the study or increase risk to the participant