SWitching to Abilify Trial (SWAT)

To evaluate the efficacy, safety and tolerance of an 12 and 26-week aripiprazole administration

This trial was designed to evaluate the efficacy, safety and tolerance of an 12 and 26-week aripiprazole administration to schizophrenic outpatients who maintain stable (no change with dosage, usage, route of the most recent antipsychotic drugs) symptoms and discontinued previous antipsychotic drugs.

Aripiprazole (10\~30 mg/day) will be orally administered for 12 weeks followed by an extension phase for a maximum of an additional 14 weeks (total of 26 weeks).

Eligibility Criteria:
Inclusion Criteria:

* Signed written informed consent
* Men and women, ages 18 to 65. Women of childbearing potential (WOCBP) must be using an adequate method of contraception to avoid pregnancy throughout the study in such a manner that the risk of pregnancy is minimized.
* Patients who have not been hospitalized during last three months
* Patients who have kept clinically stable dosage during last one month
* Patients with a diagnosis of schizophrenia and schizoaffective disorder as defined by DSM-IV criteria
* Patients whose symptoms are not optimally controlled or whose antipsychotic medication is not well-tolerated, which in the clinical judgment of the treating psychiatrist require a change of treatment.
* Patients who have received antipsychotics in the past must have shown a response to a neuroleptic medication other than clozapine.

Exclusion Criteria:

* Patients who are unwilling or unable to use an acceptable method to avoid pregnancy for the entire study period
* Women who are pregnant or breastfeeding
* Patients who are at risk for committing suicide: either having active suicidal ideation considered clinically significant or recently attempted suicide
* Patients with a diagnosis of bipolar disorder, depression with psychotic symptoms, or organic brain syndromes
* Patients who have met DSM-IV criteria for any significant Psychoactive Substance Use Disorder within the 3 months prior to Screening
* Patients considered treatment-resistant to antipsychotic medication (patients need to have shown a previous response to a antipsychotic medication other than clozapine) and patients with a significant history of intolerance to multiple antipsychotic treatments
* Treatment with a long-acting antipsychotic (i.e., haloperidol decanoate or fluphenazine decanoate) in which the last dose was within 3 weeks of randomization.
* Patients with a history of neuroleptic malignant syndrome
* Patients with epilepsy, a history of seizures (except for a single childhood febrile seizure), or a history of an abnormal EEG, severe head trauma, or stroke or who have a history or evidence of other medical conditions (e.g., congestive heart failure) that would expose them to an undue risk of a significant adverse event or interfere with assessments of safety or efficacy during the course of the trial
* Patients who would be likely to require prohibited concomitant therapy during the trial
* Patients who have previously enrolled in an aripiprazole clinical study or who have participated in any clinical trial with an investigational agent within the past month
* Prisoners or subjects who are compulsorily detained for treatment of either a psychiatric or physical (e.g., infectious disease) illness must not be enrolled into this study.