Tandospirone Combined With Atypical Antipsychotic Drugs in Schizophrenia

Inclusion Criteria: * Diagnostic and Statistical Manual of Mental Disorders-IV Edition (DSM-IV) diagnostic criteria for schizophrenia patients. * 18-65 years (including 18 and 65), male or female. * Treated with a stable dose of an AAPD for at least three months. * Informed consent was obtained (if the patient is in the acute phase of schizophrenia, does not have the capacity, their guardians need sign informed consent). * PANSS negative score ≤60. Exclusion Criteria: * Combined AxisⅠmental illness other than schizophrenia; * Taking a mood stabilizer, antidepressants, anticholinergic or anxiolytic drugs, and other drugs improve cognitive function; * Suicidal tendencies; * Have severe or unstable heart, liver, kidney, endocrine, blood and other medical disease patients * Clinically significant ECG or laboratory abnormalities were * Glaucoma and epilepsy; * Unsupervised or unable to take prescribed medication; * History of alcohol and drug abuse; * Allergic; * Pregnant or lactating woman; * Patients participate in other clinical trials during a month;