Treatment of bipolar disorder: Review of evidence regarding quetiapine and lithium

Background Lithium, the prototypical mood stabilizer, and quetiapine, a second-generation antipsychotic, are widely used acute and maintenance pharmacotherapies for bipolar disorder. The Clinical and Health Outcomes Initiative in Comparative Effectiveness for Bipolar Disorder (Bipolar CHOICE) study was the first comparative effectiveness assessment of lithium versus quetiapine (in combination with adjunctive personalized treatment), and found no overall significant differences in efficacy and safety/tolerability outcomes between lithium and quetiapine. Completion of Bipolar CHOICE offers a timely opportunity to review the evidence regarding lithium and quetiapine for bipolar disorder. Methods Controlled clinical trials and real-world observational studies that included quetiapine and lithium as monotherapy or as combination therapy were identified by literature search. Selected studies were reviewed in detail. Results Review of the available trials suggested comparable efficacy of quetiapine and lithium in acute mania, and possibly greater efficacy for quetiapine compared with lithium in acute bipolar depression and in prevention of recurrent (particularly depressive) episodes. Combination therapy including quetiapine and lithium was generally more effective than either agent alone in acute mania and bipolar maintenance, although adding lithium to quetiapine did not increase efficacy in acute bipolar depression. Safety data for quetiapine and lithium were consistent with the established profiles of the two treatments. Limitations Limitations include those of the available efficacy and effectiveness trial data. Conclusions Quetiapine and lithium have overlapping but distinctive roles in different phases of bipolar disorder, and further studies of these agents (particularly in combination with one another) are warranted.