This is a study designed to evalute the safety and efficacy of RGH-188 in the treatment of acute schizophrenia. This study will be 10 weeks in duration; 6 weeks double-blind treatment, and 4 weeks safety follow-up. All patients meeting the eligibility criteria will be randomized to one of the three treatment groups--one of two doses of RGH-188 or placebo

Inclusion Criteria:

• Male and female inpatients, 18-65 years of age, meeting DSM-IV-TR criteria for schizophrenia and having a Total Positive and Negative Syndrome Scale (PANSS) Score >=80 and <=120. A score >=4 on item P1 (delusions) or P3 (hallucinatory behavior) and a score of >=4 on item P2 (conceptual disorganization) or P6 (suspiciousness/persecution) of the PNASS

Exclusion Criteria:

• Patients with documented disease of the central nervous system that can interfere with the trial assessments, including but not limited to stroke, tumor, Parkinson's, organic brain disease, seizure disorder (except for febrile convulsions during infancy), chronic infection, or neurosyphilis; or patients who have suffered a traumatic brain injury resulting in significant impairment