Naltrexone in autistic children: behavioral symptoms and attentional learning

To assess critically the short-term efficacy and safety of naltrexone in autistic children and its effects on discrimination learning in the laboratory.

A parallel group design was employed. After a 2-week placebo baseline period, children were randomly assigned either to naltrexone or to placebo for a period of 3 weeks followed by a one-week posttreatment placebo period. Multiple raters and rating scales were employed in a variety of conditions. Forty-one children, all inpatients, ages 2.9 to 7.8 years, completed the study. Naltrexone reduced hyperactivity and had no effect on discrimination learning in the laboratory. There was a suggestion that it had a beneficial effect on decreasing self-injurious behavior. Untoward effects were mild and transient.

In the present study, naltrexone significantly reduced only hyperactivity, and no serious untoward effects were observed. The effectiveness of naltrexone in the treatment of autism and self-injurious behavior requires additional assessment in a sample of children with moderate to severe self-injurious behavior.