This study is to determine the efficacy (how well the drug works), safety, and side effects of the study medication compared to placebo in the treatment of the negative symptoms of schizophrenia in adults.

Inclusion:

• Adults aged 18-60
• Current diagnosis of schizophrenia
• Significant negative symptoms with few positive symptoms (e.g. hallucinations, delusions) and no evidence of major depression.
• Female subjects of childbearing potential must test negative for pregnancy at the time of enrollment.
• Subjects must be able to provide consent
• Must be healthy based on medical exam, laboratory tests and electrocardiogram

Exclusion:

• Female subjects who are either pregnant or nursing.
• Acute or unstable medical conditions
• Diseases of the central nervous system
• Subjects who are judged clinically to be at serious risk for suicide or violence
• Subjects with delusional disorder, psychotic disorder NOS, schizophreniform, schizoaffective disorder, bipolar disorder, attention deficit/hyperactivity disorder, major depressive disorder,alcohol or drug dependence