Lamotrigine and Lithium Combination for Treatment of Rapid Cycling Bipolar Disorder: Results From Meta-Analysis

OBJECTIVE: The objective of this study is to observe the effect of combination of lithium and lamotrigine in treatment of rapid-cycling bipolar disorder (RCBD). METHOD: We searched MEDLINE, EMBASE, Cochrane Library in English and CBM, CNKI, WANFANG, and CSSCI in Chinese to find literature from 1 January 2000 to 31 December 2020 related to the combination of lithium carbonate and lamotrigine for treatment of RCBD. RESULTS: Five comparison studies with 265 subjects of 131 cases in a study group and 134 cases in a control group met the inclusion criteria and were included for the final meta-analysis. The comprehensive analysis shows that the study group had a significant lower score in mental symptoms than the control group (Z = 2.34, P = 0.02) with a random model (X(2) = 33.02, df = 7, P < 0.01). However, the differences were only shown in PANSS (Z = 5.18, P < 0.01) and BPRS (Z = 3.08, P < 0.01). There was no difference in response rate (54.9 vs. 45.7%; OR = 1.47; 95% CI: 0.79~2.73; Z = 1.21, P > 0.05,) and remission rate (47.9 vs. 45.9%; OR = 1.05; 95% CI: 0.49~2.25; Z = 0.13, P > 0.05,) found between the two groups. The response rate of lamotrigine and lithium combination was significantly higher compare to that of monotherapy of lithium in patients with no treatment resistant (82 vs. 54%; OR = 4.26; 95% CI: 1.65~10.99; Z = 3.99, P < 0.01) with the fixed effect model (X(2) = 0.89, df = 1, P > 0.05, I(2) = 0%). CONCLUSION: The combination of lithium and lamotrigine resulted in better improvement of psychotic symptoms and higher response rate in patients with RCBP with no treatment resistant.