An open-label extension study using a variable dose (20 to 30 mg daily) of bifeprunox to evaluate long-term safety.

Inclusion Criteria:

1. Outpatients who have successfully completed Wyeth study 3168A1-313.
2. A signed and dated informed consent form for this study.
3. No major protocol violations in the previous study.

Exclusion Criteria:

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