Effect of Electroconvulsive Therapy (ECT) and Transcranial Magnetic Stimulation(TMS) on Brain Derived Neurotrophic Factor (BDNF) in Depressed Patients.

Inclusion Criteria: * MDD or bipolar disorder; * current depressive episode, ham-d17\>17 and ymrs\<8; * recommended to receive ECT or TMS as part of clinical care; * male/female; * age 18-65; * inpatient or outpatient; * comorbid dysthymic disorder, gad, or social anxiety will be included; * able to give written consent and agree. Exclusion Criteria: * current manic, hypomanic, or mixed episode, ymrs\>7; * current schizophrenia, anorexia, bulimia, substance dependence (current within past 6 months excluding caffeine and nicotine); * TMS or ECT in the last 3 months; * any other primary diagnosis; * uncontrolled medical illness; * epilepsy or severe personality disorder at the discretion of the investigators; * 3 weeks prior to first blood test, antidepressants, mood stabilizers, antipsychotics can not be added or increased; * pregnant women or women of childbearing potential not willing to use appropriate contraception, nursing women; * known intolerance or lack of response to treatment receiving as judged by the investigator; * medical conditions that would affect serum levels of BDNF; * involvement in planning and conduct of the study.