The effects of chronic naltrexone treatment in young autistic children: a double-blind placebo-controlled crossover study.

In a double-blind placebo-controlled crossover trial 23 autistic children, aged 3-7 years, were treated with a mean daily dosage of 1 mg/kg naltrexone for 4 weeks. Drug effects were monitored with behavior checklists rated by parents and teachers, and ethological playroom observations. On average, parents' checklists and playroom data could not differentiate between naltrexone treatment and placebo treatment; however, teachers significantly favored naltrexone treatment. They reported a decrease in hyperactivity and irritability. No effects of naltrexone on social and stereotypic behavior could be demonstrated.