A randomized placebo-controlled pilot study of N-acetylcysteine in youth with autism spectrum disorder

Study answer

What this study found

NAC did not significantly improve core social impairment compared with placebo, although it was well tolerated and increased peripheral glutathione. On the primary CGI-I outcome, NAC response rates were 26.7% at week 4, 38.5% at week 8, and 50.0% at week 12, with no significant between-group differences at any time point (all p values > 0.60). Clinical secondary outcomes were also not significantly different between groups for ABC, SRS, or VABS-II change from baseline to week 12 (all ps > 0.13). In contrast, week 12 glutathione was higher in NAC than placebo (780.3 vs 640.4 uM; p < 0.05).

Study & population

This was a randomized, double-blind, placebo-controlled pilot trial conducted in the United States.

Intervention

Oral N-acetylcysteine (NAC) was given as encapsulated powder capsules, titrated over the first 3 weeks to a target of 60 mg/kg/day in three divided doses, with a maximum dose of 4200 mg/day.

Key limitation

This was a small pilot study with limited power, and post-baseline analyses were based on completers rather than the full randomized sample.

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Original abstract