OBJECTIVE: To assess quetiapine effectiveness in bipolar disorder (BD) patients in a clinical setting.

METHODS: We naturalistically administered open quetiapine to outpatients assessed with the Systematic Treatment Enhancement Program for BD (STEP-BD) Affective Disorders Evaluation, and monitored longitudinally with the STEP-BD Clinical Monitoring Form.

RESULTS: 96 patients (36 BD I, 50 BD II, 9 BD NOS, 1 Schizoaffective Bipolar Type, mean +/- SD age 42.3 +/- 13.8 years, 66.7% female) received quetiapine, combined with an average of 2.5 (in 66.7% of patients at least 2) other psychotropic medications and 0.9 non-psychotropic medications, started most often during depressive symptoms (53.1%) or euthymia (37.5%). Mean quetiapine duration and final dose were 385 days and 196 mg/day (50.0% of patients took ≤75 mg/day). Quetiapine was discontinued in 38.5% of trials, after on average 307 days, most often (in 19.8%) due to CNS adverse effects (primarily sedation). In 38.5% of trials quetiapine was continued on average 328 days with no subsequent psychotropic added. In 22.9% quetiapine was continued on average 613 days, but had subsequent psychotropic added after on average 113 days, most often for depressive symptoms. In 67 trials started at Stanford, quetiapine tended to primarily maintain euthymia and relieve depressive symptoms. In 29 trials started prior to Stanford, continuing quetiapine tended to primarily maintain euthymia and relieve mood elevation symptoms. Aside from sedation, quetiapine was generally well tolerated.

CONCLUSIONS: In bipolar disorder outpatients quetiapine had a moderate (38.5%, with 385-day mean duration) discontinuation rate, and commonly did not require subsequent additional pharmacotherapy, suggesting effectiveness in a clinical setting.