Efficacy and acceptability of adjunctive n-acetylcysteine for psychotic disorders: Systematic review and meta-analysis

Introduction: N-acetylcysteine (NAC) augmentation of antipsychotic medication has been studied in psychotic disorders but the results are inconsistent. This meta-analysis aimed to evaluate the efficacy and acceptability of NAC as an augmentation strategy for psychotic disorders.Methods: PubMed, Web of Science, EMBASE, PsycINFO, Cochrane Library, and were searched until the date of November 28, 2022. The inclusion criteria were randomized controlled trials (RCTs) comparing NAC and placebo in patients with psychotic disorders. The outcomes were the psychotic symptoms measured by the Positive and Negative Syndrome Scale (PANSS) and drop-out rates.Results: A total of 594 patients from eight trials were included. The results showed that no difference was found in score changes of PANSS total, positive, negative, or general psychopathology scale scores between the NAC group and placebo group in both time points (=24 weeks and >24 weeks). There was also no statistical difference in drop-out rates between the two groups.Conclusion: For the moment, it is not appropriate to recommend NAC as an augmentation of antipsychotic medication to treat psychotic disorders in routine clinical practice.