title: N-acetylcysteine as an adjunctive therapy to risperidone for treatment of irritability in autism: a randomized, double-blind, placebo-controlled clinical trial of efficacy and safety.
abstract: OBJECTIVE
  According to the proposed interference of N-acetylcysteine (NAC) with pathophysiologic processes of autistic disorders (ADs), we aimed to assess the effectiveness and safety of NAC as an adjunct to risperidone in the treatment of ADs in a randomized, double-blind, clinical trial.
  
  
  METHODS
  The participants were referred outpatients between 4 and 12 years of age with the diagnosis of ADs and a score of more than 12 on Aberrant Behavior Checklist-Community (ABC-C) Irritability subscale score. The participants were randomized into 2 groups. One group received risperidone plus NAC, and the other group received risperidone plus placebo. The dose of risperidone was titrated between 1 and 2.0 mg/d, and the dose of NAC was 600 to 900 mg/d. The main outcome was mean decrease in the ABC-C irritability subscale score from baseline at 5 and 10 weeks. Changes in other subscales were considered as secondary outcome measures.
  
  
  RESULTS
  Forty patients completed the 10-week trial. Baseline characteristics including age, sex and body weight, as well as baseline scores in 5 subscales did not demonstrate statistically significant difference between the 2 groups. Repeated-measures analysis showed significant effect for time × treatment interaction in irritability (P = 0.01) and hyperactivity/noncompliance (P = 0.02) subscales. By week 10, the NAC group showed significantly more reduction in irritability (P = 0.02) and hyperactivity/noncompliance (P = 0.01) subscales scores.
  
  
  CONCLUSIONS
  N-acetylcysteine can be considered as an adjuvant therapy for ADs with beneficial therapeutic outcomes.
authors.affiliation: Psychiatric Research Center, Roozbeh Psychiatric Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammadali
authors.initials: M
authors.lastname: Nikoo
authors.forename: Hanieh
authors.initials: H
authors.lastname: Radnia
authors.forename: Mehdi
authors.initials: M
authors.lastname: Farokhnia
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Mohammadi
authors.forename: Shahin
authors.initials: S
authors.lastname: Akhondzadeh
mesh_terms: D000111:Acetylcysteine / Q000627:therapeutic use*; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001321:Autistic Disorder / Q000188:drug therapy / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D016166:Free Radical Scavengers / Q000627:therapeutic use*; D006801:Humans; D007508:Irritable Mood / Q000187:drug effects*; D008297:Male; D011569:Psychiatric Status Rating Scales; D018967:Risperidone / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D016166:Free Radical Scavengers; D018967:Risperidone; D000111:Acetylcysteine