A one year extension study using flexible doses, 20 or 30 mg daily, of open-label bifeprunox.

Inclusion Criteria:

1. Outpatients who have successfully completed Wyeth study 3168A1-311-US.
2. A signed and dated informed consent form for this study.
3. No major protocol violations in previous study.

Exclusion Criteria:

1. Clinically important abnormalities noted in preceding short-term study that have not resolved.
2. Use of prohibited treatments in the preceding short-term study.
3. Meeting any exclusion criteria for the preceding short-term study.