IRCT20190714044199N1.

Methods	10‐week parallel trial of N‐acetylcysteine versus placebo
Participants	Inclusion criteria: children 3‐12 years no serious medical conditions or psychiatric conditions IQ > 50 Exclusion criteria: taking any other antipsychotics apart from risperidone history of allergic reactions to risperidone or n‐acetylcysteine Location/setting: Iran Number randomised: target sample size of 66 Number of withdrawals/dropouts: not reported Gender: not reported Mean age: not reported IQ: > 50 Baseline ABC‐I or other BoC: not reported Concomitant medications: not reported History of previous medications: not reported
Interventions	Intervention (N‐acetylcysteine + risperidone) for 10 weeks: maximum of 600 mg/day + risperidone (maximum of 1.5 mg/day) Comparator (placebo + risperidone) for 10 weeks: placebo + risperidone (maximum of 1.5 mg/day) Timing of outcome assessments: baseline, week 5, week 10 (endpoint)
Outcomes	Primary outcomes: AEs Secondary outcomes: not reported
Notes	Study start date: November 2019 Study end date: not reported Source of funding: not reported Conflicts of interest: not reported