Effectiveness ofN-acetylcysteine in autism spectrum disorders: A meta-analysis of randomized controlled trials

Objective: Currently, pharmaceutical treatment options for autism spectrum disorder are limited. Brain glutaminergic dysregulation is observed in autism spectrum disorder.N-acetylcysteine, which can be converted to glutathione and subsequently release glutamate into the extracellular space, and thus reduce glutamatergic neurotransmission at synapses, is considered a potential drug for autism spectrum disorder treatment. Here, we analyzed the treatment effects ofN-acetylcysteine on autism spectrum disorder in randomized controlled trials. Study design: Updated systematic review and meta-analysis. Data sources: By systematically searching the PubMed, Embase and Cochrane Library, we obtained five randomized controlled trials. Study selection: Meta-analyses were performed to examine the improvement in autistic behaviors as measured by the Aberrant Behavior Checklist, Social Responsiveness Scale and Repetitive Behavior Scale-Revised, using mean difference with a 95% confidence interval and a random-effects model. Data Synthesis: After 8-12 weeks ofN-acetylcysteine supplementation, the pooled result of four trials revealed an improvement in Aberrant Behavior Checklist total score (mean difference = 1.31, 95% confidence interval = [0.42, 2.20]). When one trial was excluded, the sensitivity test result was stronger (mean difference = 1.88, 95% confidence interval = [0.92, 2.83]). The pooled results of three trials revealed significant improvements in hyperactivity (mean difference = 4.80, 95% confidence interval = [1.20, 8.40]) and irritability (mean difference = 4.07, 95% confidence interval = [1.13, 7.04]). Regarding Social Responsiveness Scale, the pooled result of two trials showed significant improvement in social awareness after 8-12 weeks ofN-acetylcysteine supplementation (mean difference = 1.34, 95% confidence interval = [0.09, 2.59]). No differences were observed in the pooled results of two trials using Repetitive Behavior Scale, either in the total or the subscales. Conclusion: We concluded thatN-acetylcysteine is safe and tolerable, reduces hyperactivity and irritability and enhances social awareness in children with autism spectrum disorder. However, further evidence should be sought before a general recommendation.

Automated summary

The study suggests that N-acetylcysteine may be a potential treatment for autism spectrum disorder, showing improvements in reducing hyperactivity and irritability, as well as enhancing social awareness in children. However, further evidence is needed before general recommendations can be made.