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.