Attention deficit hyperactivity disorder, or ADHD, is a commonly diagnosed childhood problem. ADHD is characterized by consistent demonstration of the following traits: decreased attention span, impulsive behavior, and excessive fidgeting or other nondirected motor activity.

All children, including children with Down syndrome, display these traits from time to time. But the child with Down syndrome may exhibit these traits more often than other children his age.

Does that mean that your child has ADHD? It may, but more often it means that a medical problem needs to be addressed, or that your child's educational program or communication method needs some adjustment. In children with Down syndrome who have difficulty paying attention, ADHD is a diagnosis of exclusion. Other problems must be ruled out first. What follows is a discussion of those problems.

Medical Problems that Can Look Like ADHD

Hearing and vision problems
In order for a child to pay attention to classroom material, she has to be able to hear and to see it. Both hearing and visual problems are common in children with Down syndrome. Ear infections are overwhelmingly common and, even if treated, can cause hearing loss for weeks. People with Down syndrome have middle ear structural abnormalities that can cause lifetime mild to moderate hearing loss.

Both near- and far-sightedness are common in Down syndrome, as well as cataracts and "lazy eye."

How can we rule out significant hearing and/or visual loss as a cause of attentional problems? To monitor hearing, an auditory brainstem response test (ABR) or otoacoustic emission (OAE) should be performed early in the child's life--by 3 months of age at the latest--as a baseline. Hearing screens should be performed annually until three years of age, and every other year thereafter. Children with abnormal hearing evaluations should be seen by an ear-nose-throat physician (otolaryngologist) to manage treatable causes of hearing loss.

A child with Down syndrome should be evaluated by an eye doctor during the first year of her life, and yearly thereafter. Some children may need more frequent followup depending on their visual diagnosis.

Gastrointestinal problems
People with Down syndrome are at increased risk for an intestinal condition called celiac disease, which is a condition in which the body cannot process a protein found in wheat and certain other grains. While typical symptoms of celiac disease include loose stools, diarrhea, and poor weight gain, the condition often presents only with subtle effects on energy and behavior. People with Down syndrome are also predisposed to significant constipation, which when severe can cause abdominal pain, lack of appetite, and restlessness.

Current recommendations for gastrointestinal monitoring include screening for celiac disease between 2 and 3 years of age. This screening should include measurement of IgA antiendomysium antibodies, as well as total IgA. Your child's primary care provider will want to review your child's bowel status with you at each visit as well.

Thyroid problems
About 30 percent of people with Down syndrome have thyroid disease at some point in life. Most have hypothyroidism, or underactive thyroid gland; a few have disease that results in overactive thyroid gland (Graves'disease). An underactive thyroid gland can, among other things, make a child very tired and apathetic.

Too much thyroid activity can cause agitation and restlessness. Therefore, both conditions can look like poor attention and behavior.

Because thyroid disease is so prevalent in this population, and because it is difficult for doctors to detect just by examining your child, an annual blood test for thyroid hormone is recommended by the Down Syndrome Preventive Checklist.

Sleep problems
Sleep disorders are extremely common in Down syndrome. These disorders are a group of conditions with many different causes but one thing in common: they all interfere with getting a good night's sleep. As a parent, you know that tired children can behave very differently from tired adults: they can become restless, whiny, and difficult to calm. And people of all ages have difficulty focusing and learning new information when they are sleep deprived.

Which sleep disorders are common in people with Down syndrome? Sleep apnea, or short periods of not breathing during sleep, is especially common. People with Down syndrome have small, often "floppy" airways, which can sometimes be completely or partially blocked during sleep by large tonsils and adenoids, or by the floppy walls of the airway collapsing as air is exhaled. Regardless of the cause of obstruction, the sleeper must awaken briefly to resume breathing. Some patients with sleep apnea awaken hundreds of times per night.

Symptoms associated with but not specific to sleep apnea include snoring, lots of "thrashing" while asleep, excessive daytime sleepiness, mouth breathing, and unusual sleep positions such as sleeping in a seated or hunched forward position.

Children suspected of having a sleep disorder should undergo a sleep study evaluation at an accredited sleep center.

Communication Problems that Can Look Like ADHD

People with Down syndrome may have many barriers to effective communication. The receptive language skills of children with Down syndrome--how well they understand what is being said--are often much stronger than their expressive language skills--how well they can say it. Parents often comment, "He knows what he wants to tell us, he just can't seem to put the words together or we can't make out what he is saying." Classroom participation is thus more difficult as well. The child may express his frustration by acting out or by inattention.

Educational problems
Children with Down syndrome have a wide range of learning styles. Your child's educational team may need to try more than one method of presenting material before finding the one that works best for your child. If material is presented in a way that is not compatible with a child's learning style--for example, oral lectures for a student who needs visual aids and prompts--that child may appear bored, fidgety, and hyperactive.

The level of the material may also be a problem. If a child is presented with concepts that are too difficult for his cognitive level, he might "tune out" and appear inattentive. A child who is bored with overly easy material also may attend poorly and act out.

Emotional problems
Because of the communication problems discussed above, people with Down syndrome may have difficulty talking about things that make them sad or angry. Major life changes such as loss or separation may prompt decreases in appropriate behavior at school or work.

...Or none of the above
If your child has had a thorough medical evaluation, the issues above have been addressed, and severe attentional problems persist, the diagnosis of ADHD may be entertained.

Children with Down syndrome have not been shown to be at higher risk for ADHD; in fact, it may be less common in Down syndrome than in typical children. Medications used to treat ADHD are probably as effective in children with Down syndrome as they are in typical children.

The most common medication used to treat ADHD is Ritalin (generic name methylphenidate). Ritalin works by stimulating groups of brain cells that function to maintain attention. Thirty minutes after a child takes it, the medication begins to take effect. Ritalin's action peaks two hours after it is taken. Four hours after the child has taken it, the medication is no longer active and has in effect left the body.

Because Ritalin is short-acting and is quickly eliminated by the body, it is usually judged to be the safest medication for ADHD. Ritalin is recommended with caution when a child has a seizure disorder, Tourette's syndrome or tics, or is making poor height and weight gains on Down syndrome growth charts.

Common side effects of Ritalin include decrease in appetite and weight loss. Less common are headaches, stomach pain, and tics.

Ritalin therapy may need to be discontinued if your child develops tics or if you and your child's doctor feel that he is not growing as expected according to a Down syndrome growth chart.