Comparison of the efficacy and safety of quetiapine and lithium for bipolar depression: A systematic review and meta‐analysis of randomized controlled trials

AIM: Pharmacological treatments recommended for bipolar depression are inconsistent across guidelines. We compared the efficacy and safety of antipsychotics and mood stabilizers for bipolar depression. METHODS: A systemic review and meta‐analysis of randomized controlled trials comparing antipsychotics and mood stabilizers for bipolar depression was conducted based on a literature search of major electronic databases. RESULTS: Three studies comparing quetiapine with lithium were identified and analyzed; no other antipsychotic‐mood stabilizer combinations were found. The meta‐analysis revealed no significant differences between quetiapine and lithium for the following outcomes: (1) remission from depressive episodes (risk ratio [RR]: 1.80, 95% CI: 0.51‐6.40, P = 0.36), (2) changes in depressive symptom (standardized mean difference: −0.22, 95% CI: −0.52‐0.08, P = 0.15), (3) changes in social function (standardized mean difference: −0.00, 95% CI: −0.19‐0.18, P = 0.98), (4) suicide‐related events (odds ratio [OR]: 2.35, 95% CI: 0.40‐13.65, P = 0.34), (5) severe adverse events (OR: 1.63, 95% CI: 0.51‐5.20, P = 0.41), (6) dropouts due to adverse events (RR: 1.19, 95% CI: 0.76‐1.87, P = 0.45, 7) dropout for any reasons (RR: 0.95, 95% CI: 0.74‐1.22, P = 0.70). CONCLUSION: Although this study found no differences in the efficacy and safety of quetiapine and lithium for bipolar depression, a comprehensive comparison of antipsychotics and mood stabilizers was not performed. Further studies are needed to clarify which of these, not just quetiapine and lithium, is more useful for bipolar depression.