Placebo-controlled acute dosage naltrexone study in young autistic children.

In a double-blind, placebo-controlled crossover trial 23 autistic children were treated with a single 40-mg dose of the opiate antagonist naltrexone. Drug effects were monitored by detailed playroom observations, actometers, and parents' checklist ratings (Aberrant Behavior Checklist, social items and target behaviors). Naltrexone treatment failed to produce significant changes in social behavior, but it did reduce irritability and target scores on behavior checklists. The playroom data indicated that naltrexone significantly affected indices of activity and attention.