In children, ADHD manifests as fidgeting, temper tantrums, running instead of walking, and troubles listening, speaking, reading or reasoning. They frequently have poor handwriting, forget homework, and can't stay focused or process what they hear. About 3 to 5 percent of school-age children have ADHD, according to the National Institute of Mental Health. Boys are more likely to be diagnosed with ADHD than girls because boys' hyperactivity is more noticeable, Faehnle said. He said ADHD is an inherited disorder.
Many parents discover they have ADHD after their children are diagnosed.
Doctors don't know what causes ADHD, but the generally accepted theory is that the brain is not producing enough chemicals called neurotransmitters to communicate and send messages, according to the book All About Attention Deficit. Without enough neurotransmitters, the brain is under-stimulated and unable to regulate activities such as paying attention. Drugs such as Ritalin stimulate the brain. Though special education students may have ADHD, not all attention deficit children are learning disabled. Ortiz Elementary School teacher Danna Mahaffey said some ADHD children become the brightest, most creative students in her fourth-grade classes once they start taking medication.