The purpose of this study is to see if differences exist in outcome in patients with schizophrenia or schizoaffective disorder who were switched from other antipsychotics to ziprasidone.

Inclusion Criteria:

• Diagnosis of schizophrenia or schizoaffective disorder
• Outpatients for at least 3 months on treatment with sulpiride, olanzapine, quetiapine, or risperidone and at least a partial beneficial response to typical antipsychotic treatment including for the current episode
• Partial improvement in symptoms that justified a switch to ziprasidone

Exclusion Criteria:

• Diagnosis of major depression or occurrence of moderate depressive symptoms
• Resistance to conventional antipsychotic drugs
• Treatment with other drugs such as antiseizure medications, antipsychotics, antidepressants, or mood stabilizing agents that might interfere with the assessement of the efficacy of ziprasidone