Repetitive transcranial magnetic stimulation (rTMS) has been successfully used to help patients with treatment resistant depression. However, its role in alleviating self injuries without suicidal ideation remained uncertain. This trial will compare the effectiveness of active accelerated intermittent theta burst stimulation (aiTBS) rTMS to a placebo control on non-suicidal self injury (NSSI) in patients with unipolar disorder and bipolar disorder.

The study will evaluate the efficacy and safety of aiTBS in unipolar and bipolar depressive patients with NSSI or suicidal thoughts and behaviors by measuring changes in clinical ratings at baseline, after all the treatments, and 2 weeks, 4 weeks after treatment. 60 inpatients will be randomized to receive active or sham interventions administered to the left dorso-lateral prefrontal cortex. The treatment will apply active aiTBS rTMS involving 1800 pulses (9 minutes), 5x daily at 60 minutes intervals for 5 days. Changes in mood and sleep from baseline to the end of the study will be measured with The Hamilton Rating Scale for Depression-17 item (HAM-D17), Hamilton Anxiety Scale (HAMA), Young's Mania Scale (YMRS), and Pittsburgh Sleep Quality Index (PSQI) . Non-suicidal self injury will be assessed by the Deliberate Self-Harm Inventory (DSHI) and the Ottawa self-injury inventory (OSI). Suicidal ideation and behaviors assessments include Beck Suicidal Scale Inventory (BSI), the Ottawa self-injury inventory (OSI) and several questions from Self-Injurious Thoughts and Behaviors Interview - Revised (SITBI-R). Improvement of cognitive dysfunction could be measured by Barratt Impulsiveness Scale-11 (BIS-11), near infrared spectroscopy (fNIRS). Treatment Emergent Symptom Scale (TESS) would be used to eliminate side effects of combined drugs at baseline and the adverse event record form (AERF) will be used to appraise the safety of aiTBS treatment using these parameters. To record the change in sensitivity to pain and examine the tolerability of the treatment for these participants, visual analogue scale (VAS) is employed after completing 5 sessions treatment every day.

Inclusion Criteria:

1. Documentation of DSM-5 criteria for current major depressive disorder (MDD) or bipolar disorder (BD) will be required for study entry.
2. Ages between 12 and 18 years
3. At least 1 caregivers to supervise the patient within 3 month.
4. A score of greater than 17 on the HAM-D17.
5. Occurrences of self injury behavior consistent with the DSM-5 criteria of NSSI more than 3 times in a month.
6. Willingness to participate in the study and sign informed consents

Exclusion Criteria:

1. Substance abusers such as psychoactive drugs or alcohol.
2. Severe physical disability and unable to complete follow-up.
3. Comorbid other major mental illnesses that meet the DSM-5 criteria, such as schizophrenia, mental retardation, dementia, severe cognitive impairment, attention deficit hyperactivity disorder, etc.
4. Currently in a manic episode, YMRS>12; rapid-cycling bipolar disorder, bipolar disorder with mixed features.
5. Suffering from any severe physical disease, neurological disease, traumatic brain injury, etc, that affects the structure or function of the brain in the lifetime.
6. Unable to read, understand and complete the assessment or to cooperate with the investigators.
7. Any implants covering a pacemaker, metallic or magnetic objects in the body, or other conditions not suitable for rTMS.
8. A history or family history of epilepsy and other contraindications to TMS.
9. Daily use of benzodiazepines (more than 2mg/d), theophylline, stimulants such as methylphenidate, anticonvulsants, bupropion, etc.
10. Those who have received systematic psychotherapy (interpersonal relationship therapy, dynamic therapy, cognitive behavioral therapy) within 3 months before baseline.
11. Other examination abnormalities considered to be inappropriate by investigators.