N-Acetylcysteine Add-On Treatment in Refractory Obsessive-Compulsive Disorder: A Randomized, Double-Blind, Placebo-Controlled Trial.
J Clin Psychopharmacol. 2012 Dec ;32(6):797-803. PMID: 23131885
From the *Isfahan Psychosomatic Research Center, Isfahan University of Medical Sciences;†
OBJECTIVE: This study aimed to evaluate the efficacy and safety of N-acetylcysteine, a glutamate-modulating agent, in patients with treatment-refractory obsessive-compulsive disorder as an adjunct to serotonin reuptake inhibitor treatment. METHODS: Forty-eight patients (36 women; mean± SD age, 30.93 ± 4.99) with obsessive-compulsive disorder who failed to respond to a course of serotonin reuptake inhibitor treatment were randomized to a 12-week intervention period of N-acetylcysteine (up to 2400 mg/d) or placebo. Primary outcome measures were the change in Yale-Brown ObsessiveCompulsive Scale (Y-BOCS) score from baseline to end point and the rate of full response in each group at the end of trial. Full response was defined as 35% or greater reduction in Y-BOCS score from baseline. RESULTS: Changes of Y-BOCS score were different over time (P<0.001) and between groups (P<0.001). N-acetylcysteine-assigned patients showed significantly improved mean Y-BOCS score (P = 0.003) and Clinical Global Impression-Severity of Illness scale score (P = 0.01) but not Clinical Global Impression-Improvement scale score at study end point. Of the patients in the N-acetylcysteine group, 52.6% were full responders at the end of the study, which was significantly higher than 15% of the patients in the placebo group (P = 0.013). CONCLUSION: This trial suggests that N-acetylcysteine may be a safe and effective option to augment standard treatment in patients with refractory obsessive-compulsive disorder.