Effectiveness and Safety of Memantine Add-on Treatment for Refractory Obsessive-Compulsive Disorder: A Meta-Analysis.

Obsessive-compulsive disorder (OCD) is a highly disabling mental illness characterised by repetitive thoughts and behaviours that disrupt daily life and impair social functioning. The purpose of this meta-analysis was to assess the efficacy and safety of memantine augmentation in treating refractory OCD. This study searched several databases from inception to January 2024 and performed a random-effects meta- analysis with subgroup analyses to evaluate the effects of the dose and duration of the intervention. Seven randomised controlled trials involving 315 participants were included, although significant heterogeneity existed between the studies. Memantine augmentation was significantly superior to a placebo in treating OCD (SMD = -1.17, 95% CI = -2.14 to -0.20, p = 0.02). Subgroup analysis revealed that memantine significantly reduced compulsive behaviours (SMD = -0.99, 95% CI = -1.45 to -0.52, p <0.001). After eight weeks of treatment, the memantine group showed a significant improvement in the total Yale-Brown Obsessive- Compulsive Scale (Y-BOCS) score compared with the placebo group (SMD = -1.06, 95% CI = -1.77 to -0.36, p = 0.003). The memantine group showed a significant improvement in the total Y-BOCS score at a dose of 20 mg/day (SMD = -1.06, 95% CI = -1.77 to -0.36, p = 0.003). Memantine significantly increased the risk of mild rash (relative risk = 7.00, 95% CI = 1.31-37.47, p = 0.02). Memantine is safe and effective for OCD augmentation therapy at 20 mg/day and a continued intervention of at least eight weeks. Key Words: Memantine, Obsessive-compulsive disorder, Augmentation, Safety, Efficacy.