Prevalence of Attention Deficit Hyperactivity Disorder ADHD in school age children is estimated to be 2% to 11%. Many preschool age children have problems with hyperactivity, short attention span, impulsivity and other behavior dyscontrol and are quite likely to continue to have difficulties in elementary school years. Many of these children are referred for diagnosis and management of their difficult behavior and are diagnosed with ADHD. Children with ADHD often display disruptive behaviors that interfere with their functioning at school, home and in the community due to symptoms of hyperactivity, impulsiveness and inattention.