Impact of obsessive-compulsive disorder on the antimanic response to olanzapine therapy in youth with bipolar disorder.

OBJECTIVE

To compare antimanic response to olanzapine therapy in youth with bipolar disorder (BPD) based on the status of comorbidity with obsessive-compulsive disorder (OCD).

METHODS

Secondary analysis of identically designed 8-week open-label trials of olanzapine therapy in youth with BPD. Severity of mania assessed with the Young Mania Rating Scale (YMRS) and Clinical Global Impression (CGI) scales.

RESULTS

Of the 52 BPD subjects (mean age 8.4 +/- 3.1 years) enrolled in the olanzapine trials (mean dose 8.5 +/- 4.3 mg/day), 39% (n = 20) met criteria for comorbid OCD. Antimanic response in BPD subjects was significantly worse in the presence of comorbid OCD (YMRS mean reduction: -5.9 +/- 13.1 versus -13.7 +/- 18.8, p = 0.04; > or = 30% reduction: 25% versus 63%, p = 0.008; CGI-Improvement score < or = 2: 25% versus 68%, p = 0.003). There was no difference in the rate of dropouts (50% versus 29%, p = 0.2) or adverse effects in BPD subjects with or without comorbid OCD.

CONCLUSIONS

Less than expected antimanic response to olanzapine therapy in the presence of comorbidity with OCD suggests that OCD is an important functionally impairing psychiatric comorbidity that may impact the efficacy of antimanic agents in youth with BPD. This study is limited by its design of secondary analysis of data from trials of an uncontrolled nature. Further prospective controlled trials are warranted.