Inattention, impulsivity, and hyperactivity are all behavioral traits of attention deficit hyperactivity disorder (ADHD) that also are normal behaviors for preschool children. Also, everyday behavior changes frequently in this age group, making it difficult to establish a pattern.

But very young children with ADHD generally have behaviors that are extreme and much more exaggerated than those of other children the same age.

Preschool children diagnosed with ADHD are not usually treated with medicine, because they are more likely to experience side effects. Parent training in techniques to improve a child's behavior is usually tried first, except in extreme cases or unusual circumstances. The Preschool ADHD Treatment Study (PATS) found that methylphenidate (Ritalin) is safe for preschool-age children in low doses. Preschool-age children taking stimulant medicine should be closely monitored.¹