RecruitingDrug trialTargeting the Neurobiology of RRB in Autism Using N-acetylcysteine: TrialThe goal of this study is to target the neurobiology of restricted and repetitive behaviors in children with autism spectrum disorder using N-acetylcysteine (NAC), a well-tolerated nutritional supplement that has shown promise for reducing symptom severity in recent small-scale trials. The findings from this research will shed light on the mechanisms of action underlying the clinical benefits of NAC and the effects of NAC on altering restricted and repetitive behavior symptom severity in children with autism spectrum disorder. This is a 12-week double-blind, randomized, placebo-controlled trial of NAC.