To evaluate open-label treatment with olanzapine in patients with borderline personality disorder (BPD).

In two concurrent studies, patients received 12 weeks of open-label olanzapine after completing 12-weeks of double-blind treatment with either olanzapine or placebo. Open-label olanzapine dosing started at 2.5 or 5mg/day and could be increased up to 20mg/day (Study 1) or 15mg/day (Study 2).

Mean ZAN-BPD total scores decreased from approximately 17 points to approximately 8-10 points during the acute phase. After 12 weeks of open-label olanzapine treatment, mean ZAN-BPD total scores were approximately 6-7 points. Patients treated with placebo during the acute phase and then open-label olanzapine showed changes in weight, prolactin, and other laboratory values similar in magnitude to those seen in acutely olanzapine-treated patients. Patients treated with olanzapine during the acute phase showed smaller changes in weight and laboratory values during the open-label extension.

Overall BPD symptom severity was low by the end of the open-label olanzapine treatment period. The types of treatment emergent adverse events appeared to be consistent with those seen previously in patients treated with olanzapine. The direction and magnitude of effects on safety measures depended on the treatment received during the prior double-blind period.