• Time to relapse, where "relapse" is defined as psychiatric hospitalization [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Increase in the level of psychiatric care required to avert hospitalization [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Substantial clinical deterioration measured by psychotic symptoms [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]

• Time to relapse, where "relapse" is defined as: Psychiatric hospitalization
• or An increase in the level of psychiatric care required to avert hospitalization
• or Substantial clinical deterioration measured by psychotic symptoms.

• Number of patients discontinuing from the study [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Number of days in hospital [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Visits to hospital emergency rooms [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Control of psychiatric symptoms [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Quality of life measures [ Time Frame: Measured throughout study ] [ Designated as safety issue: No ]
• Side effects and metabolic measures [ Time Frame: Measured throughout study ] [ Designated as safety issue: Yes ]

• Number of patients discontinuing from the study
• Number of days in hospital
• Visits to hospital emergency rooms
• Control of psychiatric symptoms
• Quality of life measures
• Side effects and metabolic measures.

This study is designed to find out whether taking antipsychotic medication once every two weeks by injection compared to taking daily oral medication will help people with schizophrenia maintain better control of their symptoms.

As is the case with many chronic illnesses, it can be challenging for people with schizophrenia to take multiple pills every day on a long-term basis. At the same time, missing or discontinuing the anti-psychotic medications that treat schizophrenia substantially increases the risk of relapse and re-hospitalization. This study will determine how effective long-acting injectable risperidone is compared to oral antipsychotic medications to help patients who have schizophrenia. Patients who enroll in the study will be randomly assigned to receive either long-acting injectable risperidone or to receive oral "atypical" antipsychotic medication. The "atypical" antipsychotics that are included for patients in the oral group are: aripiprazole, olanzapine, quetiapine, risperidone, and ziprasidone. Patients in the "oral" group will receive whichever of the five "atypical" antipsychotic medications they and their study doctor decide is best for them. Patients in the "oral" group will be allowed to switch to others of the five medications during the study if they and their doctor think that is best.

Patients in this study will be evaluated at the beginning of the study and then again every two weeks for up to 30 months (2 1/2 years). Each two-week visit will take about 20 minutes. At the visit, patients will receive medication and will be examined for side effects of the medications, their vital signs (heart rate, blood pressure, weight, and waist measurement) will be measured, and they will be asked a few questions about attendance at visits and taking medication. The visit that occurs every three months will take about one hour, instead of 20 minutes, and will include additional questions, an examination for muscle stiffness or abnormal body movements, and an interview from a member of the research team conducted using computer technology. In addition, blood and urine samples may be collected about seven times throughout the 30 months of the study treatment. Patients who enroll in this study after the halfway point of the study, may not receive a full 30 months of treatment, but it is planned that all patients will have the opportunity to receive no less than 18 months of treatment.

• Schizophrenia
• Schizoaffective Disorder

• Drug: Risperidone microspheres
• Drug: Risperidone
• Drug: Olanzapine
• Drug: Quetiapine
• Drug: Ziprasidone
• Drug: Aripiprazole
• Drug: Paliperidone

• Experimental: Participants assigned to receive long-acting injectable risperidone
• Active Comparator: Participants assigned to receive oral "atypical" antipsychotic medication

Inclusion Criteria:

• All schizophrenia and schizoaffective patients whose clinicians are considering long-term treatment with an "atypical" (second generation) antipsychotic medication
• Worsening of illness (schizophrenia) within 12 months of study entry as defined by: hospitalization, increased level of clinical care, and/or present clinical Global Impressions Severity rating of moderate or worse

Exclusion Criteria:

• First episode patients as defined by a patient who: has never received antipsychotic medication and has never been hospitalized for psychiatric illness; or, is receiving antipsychotic medication for the first time associated with a first diagnosis of schizophrenia.
• Pregnant or breastfeeding
• Patients with unstable medical conditions
• Patients with previous history of failure to respond to an adequate trial of clozapine
• Patients with a known allergy to risperidone or a previous history of failure to respond to an adequate trial of risperidone. However, patients with known allergies or failure to respond to any of the other medications (aripiprazole, olanzapine, quetiapine or ziprasidone) will not receive that medication if they are randomized to the oral medication arm, but are not excluded from the study