OBJECTIVES:The current analysis investigated the onset of antidepressant effect of olanzapine/fluoxetine combination.METHODS:Data for these post hoc analyses were obtained from a clinical trial comparing olanzapine, placebo, and olanzapine/fluoxetine combination in bipolar depression (BD). Subjects were 833 patients with a DSM-IV diagnosis of bipolar I disorder, depressed. The Montgomery-Asberg Depression Rating Scale measured depressive symptoms. Multiple analytic methods were applied, including traditional (mean differences) analysis, pattern analysis, survival analysis of sustained response, mixed-effects regression, and area-under-the-curve analysis.RESULTS:Traditional analysis showed significantly greater improvement in depression scores at week 1 for olanzapine/fluoxetine combination versus placebo (-9.55 versus -5.08, p < 0.001) and for olanzapine versus placebo (-8.31 versus -5.08, p < 0.001). Pattern analysis revealed olanzapine/fluoxetine combination had a significantly greater percentage of early persistent responders than placebo or olanzapine (32.4% versus 12.7%, p < 0.001; and 18.3%, p < 0.05, respectively). Survival analysis showed a significantly shorter time to sustained response for the combination versus placebo (p < 0.001), for olanzapine versus placebo (p = 0.04), and for the combination versus olanzapine (p = 0.03). Mixed-effects regression analysis revealed a significant therapy-by-time interaction (p < 0.001). Early area-under-the-curve analysis revealed a significantly greater percentage of improvement for the combination versus placebo (26.7% versus 13.9%, p < 0.001) and for olanzapine versus placebo (22.0% versus 13.9%, p < 0.001).CONCLUSIONS:Based on consistent results from related methods of measuring onset, olanzapine/fluoxetine combination demonstrated rapid onset of antidepressant effect (within 7 days) compared to placebo that was sustained over 8 weeks of treatment in a sample of BD patients. Using multiple statistical techniques may help profile a drug's onset of effect.

BACKGROUND:This 8-week, double-blind, multicenter study was undertaken to replicate, in a larger sample of patients with treatment-resistant major depressive disorder (MDD; DSM-IV criteria), the results of a pilot study of the olanzapine/fluoxetine combination. METHOD:The study was begun in August 1999. The primary entry criterion was a history of failure to respond to a selective serotonin reuptake inhibitor (SSRI). Patients (N = 500) who subsequently failed to respond to nortriptyline during an open-label lead-in phase were randomly assigned to 1 of 4 treatment groups: olanzapine (6-12 mg/day) plus fluoxetine (25-50 mg/day) combination, olanzapine (6-12 mg/day), fluoxetine (25-50 mg/day), or nortriptyline (25-175 mg/day). The primary outcome measure was baseline-to-endpoint mean change in score on the Montgomery-Asberg Depression Rating Scale (MADRS). RESULTS:At the 8-week study endpoint, MADRS total scores decreased by a mean 8.7 points from baseline (28.5) with the olanzapine/fluoxetine combination, 7.0 points from baseline (28.4) with olanzapine (p = .08), 8.5 points from baseline (28.4) with fluoxetine (p = .84), and 7.5 points from baseline (28.8) with nortriptyline (p = .30), with no significant differences among the therapies. The olanzapine/fluoxetine combination was associated with significantly (p < or = .05) greater improvement (decrease) in MADRS scores than olanzapine at weeks 2, 4, 6, and 7; than fluoxetine at weeks 2 through 5; and than nortriptyline at weeks 1 through 4. A post hoc analysis of a subgroup of patients who had an SSRI treatment failure during their current MDD episode (N = 314) revealed that the olanzapine/fluoxetine combination group had a significantly (p = .005) greater decrease in MADRS scores than the olanzapine group at endpoint. Safety data for the olanzapine/fluoxetine combination were similar to those for its component monotherapies. CONCLUSIONS:The olanzapine/fluoxetine combination did not differ significantly from the other therapies at endpoint, although it demonstrated a more rapid response that was sustained until the end of treatment. The results raised several methodological questions, and recommendations are made regarding the criteria for study entry and randomization.

BACKGROUND Treatment-emergent mania is a potential risk when patients with bipolar disorder are treated with antidepressant agents. These subanalyses compare treatment-emergent mania rates in bipolar I depressed patients treated with olanzapine, placebo, or olanzapine/fluoxetine combination. METHOD In this 8-week, double-blind investigation, patients with bipolar I depression (DSM-IV criteria) (N = 833, baseline Montgomery-Asberg Depression Rating Scale total score > or = 20) were randomly assigned to olanzapine (5-20 mg/day, N = 370), placebo (N = 377), or olanzapine/fluoxetine combination (6/25, 6/50, or 12/50 mg/day; N = 86). Treatment-emergent mania was evaluated with the Young Mania Rating Scale (YMRS), the Clinical Global Impressions-Bipolar Edition (CGI-BP) Severity of Mania scale, and adverse events records. RESULTS Overall rates of study discontinuation due to mania were low and not significantly different among the therapy groups (p = .358). Incidence of treatment-emergent mania (defined as a YMRS score < 15 at baseline and > or = 15 at any subsequent visit) did not differ significantly among therapy groups (olanzapine 5.7%, placebo 6.7%, olanzapine/fluoxetine combination 6.4%; p = .861). Subjects receiving olanzapine or olanzapine/fluoxetine combination had greater mean decreases in YMRS scores than those receiving placebo (p < .001 for both). Subjects receiving olanzapine or olanzapine/fluoxetine combination also had greater mean decreases in CGI-BP scores than those receiving placebo (p = .040 and p = .003, respectively). CONCLUSION These results suggest that olanzapine/fluoxetine combination does not present a greater risk of treatment-emergent mania compared to olanzapine or placebo over 8 weeks of acute treatment for bipolar I depression. Due to the cyclical nature of bipolar disorder, patients taking olanzapine/fluoxetine combination for bipolar depression should still be monitored for signs or symptoms of emerging mania.