Combination Therapy of Serotonin Reuptake Inhibitors and Memantine for Obsessive- Compulsive Disorder: A Meta-Analysis of Double-Blind, Randomized, Placebo-Controlled Trials

We performed a meta-analysis to determine whether combination therapy with serotonin reuptake inhibitors (SRIs) and memantine (MEM) was beneficial for the treatment of obsessive- compulsive disorder. This study included three double-blind, randomized, placebo-controlled trials. MEM+SRI was superior to placebo+SRI with regard to response rate [primary outcome, n = 97; risk ratio = 0.22; 95% confidence intervals (CI) = 0.12-0.42; p < 0.00001; I 2 = 0%; number needed to treat = 2], the Yale- Brown Obsessive- Compulsive Scale total [standardized mean difference (SMD) = - 4.56; 95% CI = - 8.50, - 0.62; p = 0.02], obsession subscale (SMD = - 4.39; 95% CI = - 5.94, - 2.85; p < 0.00001), and compulsion subscale score (SMD = - 4.60; 95% CI = - 7.64, - 1.55; p = 0.003). No significant differences in any safety outcome were found between the groups.