RETRACTED: Effect of N-acetyl cysteine (NAC) supplementation on positive and negative syndrome scale in schizophrenia: a systematic review and meta-analysis of randomised controlled trials (Retracted Article)

ObjectiveTo conduct a systematic review and meta-analysis of published randomised controlled trials on the efficacy of NAC supplementation on positive and negative syndrome scale in schizophrenia.MethodsA meta-analysis was conducted, and studies were identified by a search of electronic databases from inception to May 2018. Combined and stratified analyses were used.ResultsSeven trials were identified, and data from n=447 participants were included. Pooled analysis showed improvement of positive and negative syndrome scale following NAC treatment compared with placebo, for total (SMB=-0.96) [95% CI -1.69, -0.24; P=0.009], general (SMB=-1.04) [95% CI -1.80, -0.27; P=0.008] and negative (SMB=-0.73) [95% CI -1.29, -0.17; P=0.01] scores, respectively. Significant heterogeneity was found, and subgroup analysis showed significant reductions in studies with a treatment duration of 24weeks, with a considerable effect size on total, general, and negative scores (Total SMD=-0.83; General SMD=-0.67; Negative SMD=-1.09) following NAC.ConclusionsNAC improved all aspects of positive and negative syndrome scale in schizophrenic populations and may be more efficacious with treatment durations up to 24weeks.