EFFECTS OF METHYLPHENIDATE ON IMPULSIVE RESPONDING IN CHILDREN WITH ATTENTION-DEFICIT HYPERACTIVITY DISORDER

The present investigation examined the effects of methylphenidate on i mpulsivity in children with attention-deficit hyperactivity disorder ( ADHD). A task was designed to measure empirically the ADHD child's pro clivity to blurt out incorrect answers before giving a final and/or co rrect response. Twenty-six ADHD children referred for double-blind pla cebo-controlled assessment of medication responsiveness and 14 non-ADH D controls were given a visual search word-matching task to assess imp ulsive responding. An analysis of covariance showed that ADHD children on methylphenidate made fewer impulsive errors than ADHD children on placebo. The control group made fewer impulsive errors than the ADHD c hildren in the placebo condition, but the performance of the ADHD chil dren on medication approximated the performance of the children withou t ADHD. These preliminary findings suggest that the word-matching task may be a useful tool for assessing impulsive responding and determini ng the benefits of stimulant medication on impulsivity.