- Generally healthy, men and women, aged 18 to 65.
- Hospitalization because of an acute exacerbation of schizophrenia with a diagnosis of
schizophrenia established greater than 1 year.
- Ability to remain hospitalized for the duration of the screening period and for 4
weeks of double-blind treatment.
- Current Axis I primary psychiatric diagnosis other than schizophrenia (DSM-IV-TR
criteria).
- Current diagnosis or history of substance abuse or dependence (DSM-IV-TR criteria),
including alcohol (except for nicotine), within 3 months before baseline (day -1).
- Subjects taking high or chronic doses of benzodiazepine at the screening evaluation
who, in the investigator's judgment, would be likely to have severe withdrawal
symptoms upon discontinuation.