Inclusion Criteria:  The Chinese Version of Modified Schedule of Affective Disorder and Schizophrenia-Life Time (SADS-L) and DSM-IV-TR will be conducted for confirmation of the diagnosis of BD-II. Aged 20-65. HDRS and YMRS will be used to evaluate severity of mood symptoms. Only patients in deressive state (HDRS≧18) will be recruited.  Exclusion Criteria:  Any DSM-IV-TR Axis I diagnosis, including organic mental disorders, substance use disorder, and other major and minor mental illnesses other than BD-II. Any significant medical illness. Any neurological disorders. Any poorly controlled physical illness that might influence the interview and study results. Any form of metal implants. Any history of seizures, or medications known to lower seizure threshold. History of exposure to TMS or electroconvulsive therapy.