"I know what's it's like to grow up with ADHD and how important it is for parents, caregivers and patients to have access to accurate information," said Pennington, who hosts ABC's Extreme Makeover: Home Edition.

"I hope that by ... sharing how support and treatment has made a difference in my life, I'll help other kids and families understand that there are people out there ready to help them, and that it's possible to live a productive life with ADHD," he added.

ADHD experts, English- and Spanish-speaking physicians, school nurses, educators and advocates, will answer calls at the toll-free telephone hotline, 1-888-ASK-ADHD. In addition, a confidential, one-on-one forum will be available on the Internet at http://www.adhdexpertsoncall.com/ throughout the day.

Real Handicap

ADHD affects approximately 3 to 7 percent, or approximately two million, school-age children in the US. A neurological brain disorder, it manifests as a persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequent and severe than is typically observed in individuals at a comparable age and maturity.

ADHD symptoms can have a profound effect on a child's quality of life and can be serious enough to interfere with academic accomplishments. Children with ADHD also may have problems maintaining friendships, focusing on sports and other after-school activities, and relating well within their own families.

A diagnosis requires that these behaviors create a real handicap in at least two areas of life, such as school, home or social settings.

Untreated ADHD may have long-term adverse effects on academic performance, vocational success and social-emotional development. It also may heighten risk for drug abuse, antisocial behavior and poor self-esteem, research suggests. Genetics are thought to play a role. Many children diagnosed with ADHD have a first-degree relative with the disorder.

There is no cure for ADHD, but physicians, parents, teachers and nurses are finding ways to help children with the condition adapt to their academic, social and work environments.

Adults with ADHD

ADHD is not confined to children; an estimated 4 percent of the US adult population also may be affected.

Its repercussions may have limited adults from reaching their full academic and occupational potential, and diminished their satisfaction with themselves and their relationships, according to a recent national survey.

Among its findings:

Adults with ADHD are more likely to engage in harmful or antisocial behaviors, like smoking and drug use;

Where to Turn

The experts participating in ADHD Experts on Call cannot provide specific medical advice for patients or parents, or recommend a particular course of action, but they will provide helpful information on a variety of related topics:

"While this program doesn't replace a physician visit, parents and adult patients can learn valuable information about ADHD symptoms, diagnosis, support groups and treatment options that can help them better understand the disorder," said Dr. David Goodman, Director of the Adult Attention Deficit Disorder Center of Lutherville, Md.

"Despite the widespread prevalence of ADHD, many parents, patients, and caregivers are confused by conflicting information about the disorder and don't know where to turn for help," he noted.