This is a post-market surveillance, and the treatment to patients will be depended upon the decision based on physician's clinical judgment. The health profiles during the switching period, after 12 weeks short-term use, and after 52 weeks long-term use of aripiprazole will be recorded and evaluated.

Further study details as provided by Taiwan Otsuka Pharmaceutical Co., Ltd.

Inclusion Criteria:

1. Male or female patients between the ages of 18 to 65.
2. Having a DSM-IV diagnosis of schizophrenia or schizoaffective disorder.
3. Who are currently taking antipsychotic drugs and clinically intolerable or inadequately controlled that is based upon the clinical judgment of the investigator.

Exclusion Criteria:

1. Pregnant or breast feeding women or planning a pregnancy.
2. Patient received electroconvulsive therapy within 4 weeks before the Screening Visit.
3. A known allergy reaction to any antipsychotic medication (including but not limited to haloperidol, chlorpromazine, thioridazine, pimozide, risperidone, quetiapine, ziprasidone).
4. Patient has clinically relevant organic, neurological, or cardiovascular diseases.
5. Patient has a history of drug or alcohol abuse within the last 12 weeks.
6. Acute psychosis, acute suicidal ideation, or any acute psychiatric condition that might require emergent intervention.
7. Any clinical condition or significant concurrent disease judged by the investigator to complicate the evaluation of the study treatment.
8. Having participated other investigational drug study and taken the investigation drug within one month prior to study entry.
9. Depot neuroleptics should be discontinued at least 2 months prior to enrollment.