Olanzapine versus placebo and haloperidol: quality of life and efficacy results of the North American double-blind trial.

This double-blind study evaluated the impact of treatment with olanzapine compared with haloperidol, and placebo on improvements in symptomatology and quality of life in patients with a DSM-III-R diagnosis of schizophrenia. A total of 335 patients was randomized to five treatment groups; olanzapine 5 +/- 2.5 mg/day, olanzapine 10 +/- 2.5 mg/day, olanzapine 15 +/- 2.5 mg/day, haloperidol 15 +/- 5 mg/day, and placebo. Patients responding to treatment during the 6-week acute phase were eligible to enter a 46-week extension. Efficacy measures included the brief psychiatric rating scale total, scale for assessment of negative symptoms summary, and clinical global impressions severity scores. Quality of life was evaluated using the quality of life scale. Data analyzed after 24 weeks of therapy showed that olanzapine was significantly superior to placebo in reducing clinical severity and significantly superior to haloperidol in reducing negative symptoms in patients responding to acute treatment. Furthermore, improvement in quality of life was observed in olanzapine-treated responders.