Inclusion Criteria:

• DSM-IV diagnosis of schizophrenia and schizoaffective disorder and not experiencing an acute exacerbation of severe psychosis
• Stable antipsychotic drug treatment for at least 4 weeks of Abilify or Haldol or willing to switch to either of these two APDs.
• Able to execute written informed consent.
• Males and females, between the ages of 18-55 years old, in good health (based on medical history, physical examination, electrocardiograms, and clinical laboratory tests)
• All races and ethnicities fluent and literate in English.

Exclusion Criteria:

• Diagnosis of DSM-IV alcohol or substance abuse within the last month or DSM-IV alcohol or substance dependence within the last 3 months.
• Patients on a stable regimen of antipsychotic medication (other than Haldol or Abilify) for a minimum of 3 months who are not experiencing psychotic symptoms.
• Clinically significant abnormal pre-admission vital signs, EKGs, or clinical laboratory evaluations, in which the principle investigator deems the subject-volunteer ineligible for the study.
• Any patient scheduled to undergo any surgical procedure during the duration of the study
• Patients suffering an acute psychotic episode within the previous 30 days as determined by the attending physician or Principal Investigator.
• Patients on any antihistaminergic antipsychotic medications who are not willing to switch to either Haldol or Abilify.
• Any patient who has received any known hepatic or renal clearance altering agents (e.g., erythromycin, cimetidine, barbiturates, phenothiazines, etc.) for a period of 3 months before the first dose of study medication
• Patients taking any concurrent medications for a major medical illness.
• Any patients who test positive for HIV.
• Any patient testing positive for Hepatitis B or C whose liver panel (taken during clinical laboratories) reports clinically significant abnormalities of liver enzyme ranges suggesting a cirrhotic stage.
• Any patient who has donated plasma or blood within 30 days before the first dose of study medication
• Concurrent treatment with electroconvulsive therapy.
• Pregnant women, women in the child bearing age without an efficacious contraceptive device, or women who are breast feeding.
• Mental capacity is limited to the extent that the patient cannot provide legal consent or understand information regarding the side effects or tolerance of the study drug
• Any patient judged by the principal investigator to be inappropriate for the study.