In this double-blind, placebo-controlled study the administration of
haloperidol resulted in significant decreases in behavioral symptoms and in
general clinical improvement in 40 autistic children ages 2.33 to 6.92
years. Haloperidol also produced greater facilitation and retention of
discrimination learning in the laboratory. No adverse effects were observed
at therapeutic doses, which ranged from 0.5 to 3.0 mg/day or 0.019 to 0.217
mg/kg per day.