Study Of An FDA-approved Drug As Additional Therapy In Patients With Schizophrenia

Inclusion criteria: Diagnosed with schizophrenia. Exhibits persistent positive symptoms that have persisted for a minimum of 3 months prior to screening. Continuously taking 1-2 specific atypical antipsychotics for a minimum of 3 months and must be on a stable dose for at least 1 month prior to entering the study. Participant or a legal guardian is able to understand and sign the consent form. Exclusion criteria: PANSS (Positive and Negative Syndrome Score) total score increases or decreases by more than 20% between the Screening and Baseline visits. Predominant Axis I disorder other than schizophrenia within 6 months prior to screening. History of clinically significant or unstable medical disorder or treatment that would interfere with the study. History of autistic disorder or another pervasive developmental disorder, organic brain disease, dementia, stroke, epilepsy or a history of seizures requiring treatment (this does not include febrile seizures as a child), or those who have suffered a traumatic head injury. Taking psychotropic or primarily centrally active medication at screening. Use of antidepressant medications or mood stabilizers within 1 month of screening.