Nine children, eight boys and one girl, ages 4 to 16 yrs, with a diagnosis of autism, were treated with methylphenidate (10-50 mg/day) as outpatients at Columbia Presbyterian Medical Center, Babies' Hospital Pediatric Psychiatric Clinic, New York. All were hyperactive, impulsive and mentally retarded. All showed significant improvement on the Conner's Teacher and Parent Questionnaire scores during treatment with the stimulant. No significant side-effects were noted or worsening of stereotyped movements. 
COMMENT. The beneficial effect of methylphenidate on the behavior of autistic children, at variance with many previous reports, is confirmed in a randomized trial of the drug in a 6-year-old autistic boy reported in the same journal from the Western Psychiatric Institute, Pittsburgh, PA . Negative effects on mood and tantrums were outweighed by positive effects on attention and activity, destructive behavior and stereotyped movements. These reports fail to support previous statements that stimulants are ineffective and contraindicated in hyperactive autistic children.  writing on treatment refers to a basic cognitive deficit which underlies language and behavior problems in autistic children. Provided that methylphenidate does not exacerbate psychotic behavior, its known effects in promoting cognitive development could be beneficial.