efficacy of n-acetylcysteine augmentation on obsessive compulsive disorder: a multicenter randomized double blind placebo controlled clinical trial

objective: glutamate is considered a target for treating obsessive-compulsive disorder (ocd). the efficacy and safety of the nutritional supplement of n-acetylcysteine (nac) as an adjuvant to serotonin reuptake inhibitor (ssri) for treating children and adolescents with ocd has never been examined. methods: this was a 10-week randomized double-blind placebo-controlled clinical trial with 34 ocd outpatients. the patients received citalopram plus nac or placebo. yale-brown obsessive-compulsive scale (ybocs) and pediatric quality of life inventory (pedsql™) were used. adverse effects were monitored. results: ybocs score was not different between the two groups at baseline, but the score was different between the two groups at the end of this trial (p<0.02). the ybocs score of nac group significantly decreased from 21.0(8.2) to 11.3(5.7) during this study. however, no statistically significant decrease of ybocs was found in the placebo group. the cohen’s d effect size was 0.83. the mean change of score of resistance/control to obsessions in the nac and placebo groups was 1.8(2.3) and 0.8(2.1), respectively (p = 0.2). however, the mean score of change for resistance/control to compulsion in the nac and placebo groups was 2.3(1.8) and 0.9(2.3), respectively. cohen’s d effect size was 0.42. the score of three domains of quality of life significantly decreased in n-acetylcysteine group during this trial. however, no statistically significant decrease was detected in the placebo group. no serious adverse effect was found in the two groups. conclusion: this trial suggests that nac adds to the effect of citalopram in improving resistance/control to compulsions in ocd children and adolescents. in addition, it is well tolerated.