ABSTRACT
WHAT IS KNOWN AND OBJECTIVE: The underlying pathophysiology of autism spectrum disorder (ASD) has been linked to immune dysregulation, oxidative stress and excitation-inhibition imbalance. Among associated symptoms of ASD, management of irritability has gained considerable attention as it complicates adjustment of ASD patients and thus necessitates its pharmacological treatment. Resveratrol is a plant phytoalexin, which has been demonstrated to have neuroprotective effects through its anti-inflammatory and antioxidant properties. This double-blind, placebo-controlled randomized trial was designed to assess the potential therapeutic effects of resveratrol plus risperidone on irritability of ASD patients. METHODS: Sixty-two patients were assigned randomly into two groups of resveratrol and placebo. Both groups were treated with risperidone twice daily starting at a dose of 0.5 mg with a dose increase of 0.5 mg per week (for the first 3 weeks). Resveratrol dosage was 250 mg twice per day from the beginning of the study. Using the Aberrant Behavior Checklist-Community (ABC-C), patients were assessed for ASD-related behavioural symptoms at baseline, week 5 and week 10. The frequency of adverse events was recorded using a checklist containing 25 possible side effects, including general, gastrointestinal, neurological and cardiovascular complications. RESULTS AND DISCUSSION: Improvements in primary outcome measure (irritability) and three secondary outcome measures (lethargy/social withdrawal, stereotypic behaviour and inappropriate speech subscales) in the resveratrol group were statistically similar to those in the placebo group. The repeated measures analysis showed no time × treatment interaction on these subscale scores. In contrast, patients in the resveratrol group showed greater decline in hyperactivity/non-compliance score as a secondary outcome measure (mean difference [CI = 95%] = 4.51 [0.10-8.92], t = 2.04; P = .04), and repeated measures analysis showed significant effect for time × treatment effect on this subscale score (F = 3.81; df = 1.30; P = .043). There was no significant difference in number and severity of adverse events between the two groups. WHAT IS NEW AND CONCLUSION: This clinical trial demonstrated no significant effect for adjunctive treatment with resveratrol on irritability of patients with ASD. However, it provided preliminary evidence indicating that resveratrol could improve hyperactivity/non-compliance of ASD patients.