Aim: 1. To confirm that patients with predominant negative symptoms in schizophrenia have deficits in frontal cortical dopamine release when compared with healthy control and patients with positive symptoms.

2. Our previous study found patients with negative symptoms have more possibilities to have disorders in glucose metabolism, we wonder whether dopamine release, negative symptoms or glucose metabolism can be improved by iTBS.

Study design: Case control study.

Eligibility Criteria: Predominant negative symptoms for Positive and Negative Syndrome Scale factor score for negative symptoms of 24 or more, and score of 4 or more on at least two of three core negative PANSS items, PANSS for positive symptoms of 19 or less, HAMD depression scale of 16 or less. Predominant positive symptoms for PANSS for positive symptoms of 20 or more. Healthy control will be recruited matching the age and sex of patient groups, Outcome Measures: Oral glucose tolerance test (OGTT), PET dopamine imaging.

Inclusion Criteria for negative group

• diagnosed with schizophrenia according to ICD-10 or DSM-V
• Positive and Negative Syndrome Scale factor score for negative symptoms of 24 or moreand score of 4 or more on at least two of three core negative PANSS items
• PANSS for positive symptoms of 19 or less, and HAMD depression scale of 16 or less.
• drug-naive Inclusion Criteria for positive group
• PANSS for positive symptoms of 20 or more
• drug-naive

Exclusion Criteria:

• drug or alcohol addiction
• diagnosed with other major mental disorders according to ICD-10 or DSM-V