Efficacy and safety of N-acetylcysteine as add-on therapy in the treatment of obsessive-compulsive disorder: A systematic review and meta-analysis

Objectives: We aimed to investigate the role of N-acetylcysteine (NAC), a glutamate-modulating agent, in the treatment of obsessive-compulsive disorder (OCD). Methods: We searched PubMed, Scopus, and Medline for relevant clinical studies discussing the efficacy and safety of NAC in patients with OCD. Data from the Yale-Brown Obsessive Compulsive Scale were extracted and pooled in a random effect model meta-analysis using RevMan version 5.3. Results: Five RCTs were included with a total number of 212 patients who were assigned in a 1:1 ratio to either NAC or placebo. Doses ranged from 2000 to 3000 mg. Regarding the Yale-Brown Obsessive Compulsive Scale, which was the primary outcome, the overall effect size favored NAC (MD = −2.97, 95% CI [-4.93, −1.02], P = 0.003). Adverse events were not significantly higher in the NAC group compared to the placebo. Conclusion: Evidence suggests that NAC may be a promising agent for the treatment of OCD patients. Further studies with larger sample sizes are still needed to support these findings and reach a conclusion regarding NAC's efficacy in reducing the symptoms of OCD.