TBS,TMS, Suicidal Ideation, Magnetic Resonance Imaging, Dorsolateral Prefrontal Cortex, Ventrolateral Prefrontal Cortex

Inclusion Criteria:

1. Age \> 50 years.
2. Major depressive disorder (MDD).
3. Right handiness
4. with a score ≥ 12 on the Beck Scale of Suicidal Ideation (BSSI) and a score of at least 3 on Question #3 (Suicide: 3 ideas and gestures of suicide) of the HAMD

Exclusion Criteria:

1. Inability to provide informed consent.
2. Dementia, as defined by MoCA 23/24. Other major mental or current psychotic symptoms
3. Active current suicidal intent as evidenced or the endorsement of an actual attempt, interrupted attempt,
4. Have known preexisting noise-induced hearing loss, concurrent treatment with ototoxic medications, or with cochlear implants are on medications known to lower seizure threshold.
5. Alcohol or other substances abuse of or dependence on within the past 3 months Organic brain, head trauma,
6. Elevated risk of seizure due to TBI
7. Participation in concurrent clinical trial
8. Non-correctable clinically significant sensory impairment (i.e., cannot hear well enough to cooperate with interview).
9. Unstable medical illness, including delirium, malignancy, uncontrolled diabetes mellitus, hypertension, hyperlipidemia, or cerebrovascular or cardiovascular risk factors that are not under medical management. Unstable cardiac disease or recent (\<3m) myocardial infarction
10. Mental implement in the brain, claustrophobia
11. Ever received ECT, TMS Consent procedures.