Effects of atypical antipsychotics on cognitive functioning in schizophrenia

INTERVENTION: Administration of atypical antipsychotics (aripiprazole, olanzapine, risperidone , quetiapine) CONDITION: Schizophrenia PRIMARY OUTCOME: Neuropsychological tests; ‐Rey‐Osterrieth Complex Figure Test; ‐Rey Auditory Verbal Learning Test; ‐Trail Making Test; ‐Modified Stroop Test; ‐Word Fluency Test; ‐Digit Span; ‐Brown‐Peterson Task; ‐Reflection Task; ‐Sense of agency Task; Neuroeconomics Related Task: performance and the brain activation in ventral striatum and prefrontal lobe during the task. SECONDARY OUTCOME: PANSS (Positive and Negative Syndrome Scale); Drug‐Induced Extrapyramidal Symptoms Scale (DIEPSS); Blood test INCLUSION CRITERIA: 1. Patients with schizophrenia diagnosed by DSM‐IV 2. Patients agree to participate in the study on a written informed consent form. 3. Patients should be able to receive examination and assessment on designated date. 4. Patients with a total score of GAF ranging 11 to 90 and a score of severity in CGI‐SCH ranging 3 to 6 are included. Moreover, we select patients with chlorpromazine‐conversion dosage of 150mg to 2000mg/ day at baseline.