Hyper for life? ADHD or attention deficit hyperactivity disorder, is the most common behavioral disorder among teens. What is it, and can it be cured? (Mental Health/Brain Chemistry).

It's hard not to pay attention to Sam: He never can seem to sit still. Nervous energy jolts through his body, making it intensely difficult for him to focus on schoolwork, keep track of assignments, and not speak out of turn. Other times he's so distracted by daydreams that the real world--honking horns or reprimanding teachers--go unnoticed. "It's just hard to pay attention to anything, really," says the 13-year-old from Illinois. "And when my parents ask me to do a lot of things at once, like chores and homework, it's too hard to remember."

Sam's conduct may sound annoying or unnerving. But he suffers from a behavioral disease called attention deficit hyperactivity disorder, or ADHD. It affects 2 million kids, or roughly 3 to 5 percent of all U.S. children and adolescents, according to the National Institute of Mental Health (NIMH). And for reasons still not clear, it impacts three times as many boys as girls.

"Everybody has problems with attention sometimes, everybody's mind wanders," says Robert Resnick, a psychologist at Randolph-Macon College in Ashland, Virginia. "But with ADHD, a short attention span is the norm. You spend most of your time trying to catch up because you've forgotten assignments, misplaced books, or lost your house keys."

In the past, ADHD has been tricky to diagnose. It isn't a disease with overt physical symptoms--like a fever, rash, or swollen glands. Instead, it makes its mark inside the body and disrupts intricate brain chemistry, which in turn spurs erratic behavior. Now medical technology is helping doctors zero in on the hidden markers of ADHD, making diagnosis increasingly easier and more reliable.

Read our Q&A to learn more about the growing body of research on ADHD, and how it's treated.

Q. What is ADHD, and what are its symptoms?

ADHD is a behavioral disorder: It's an individual's telltale actions--trouble organizing activities like chores and homework, inability to pay attention to details or follow instructions, and frequently misplacing belongings, for example--that alert experts to ADHD. Kids with ADHD often fidget constantly in their seats, run around wildly when they shouldn't, or seem to chatter and interrupt others uncontrollably--signals that typify the "hyperactive" component of the disease.

Symptoms usually appear before age 7 and need to persist for at least six months before a doctor can diagnose ADHD. But pinning down ADHD is tricky--various conditions produce similar symptoms. Doctors must first rule out neurological or nervous-system diseases, learning disabilities, and psychological conflicts stemming from abuse, say, or a family divorce, explains Stephen Hinshaw, a psychology professor at the University of California at Berkeley: "It's a low-tech diagnosis, but it takes several hours of assessment."

Q. What causes ADHD?

Researchers still don't know for certain, but they're probing the links between genes (hereditary material), brain chemistry, and behavior. Many experts now think ADHD is genetic and runs in families. In fact, the Centers for Disease Control estimates genetic factors account for up to 80 percent of cases.

New research also indicates that in ADHD sufferers, brain areas that control impulses and maintain attention--such as the prefrontal cortex and basal ganglia--don't function properly (see diagram, right).

Other evidence suggests that neurotransmitters, chemical messengers in the brain like dopamine and norepinephrine, may be deficient. "These chemicals help you pay attention and control behavior," says James Christ, a Woodbridge, Virginia, psychologist.

Q. Why aren't more girls diagnosed with ADHD?

For years, researchers considered ADHD mostly a male malady. Now they realize girls suffer too: Girls with ADHD tend to talk excessively or act impulsively; girls also more commonly exhibit the "inattentive" type of ADHD, characterized by constant daydreaming or forgetfulness: "These kids are far less likely to be noticed by parents or teachers," says Hinshaw. "They suffer in silence in some ways."

Q. How is ADHD treated?

Ritalin is the most-often prescribed drug for ADHD. It's actually the brand name of a stimulant, a drug that activates the central nervous system (brain and spinal cord). How can a drug that revs up your body treat a disease whose primary symptom is hyperactivity? "The medication works by increasing brain levels of the neurotransmitters dopamine and norepinephrine," says Christ. At normal levels in the brain, these chemicals help control attention, stimulate motivation, and modify unsocial behavior.

But stimulant drugs often trigger side effects like loss of appetite, upset stomach, and difficulty sleeping. Sam took both Ritalin and another stimulant drug for three years. While the medication helped him focus, it also made him sleepless, and this year he's been coping drug free.

Last November, the Food and Drug Administration approved a new non-stimulant drug called atomoxetine to specifically treat ADHD. "Atomoxetine has potential benefits for patients who can't tolerate stimulants," says Dr. Christopher Kratochvil, a psychiatrist at the University of Nebraska. "It's another alternative to treat ADHD."

But medication is just one part of the treatment plan. In addition, says Robert Resnick, teachers can help make the world more "ADHD friendly" by encouraging affected students to sit at the front of the class, and handing out printed assignments for them. Families can help by creating a clean, quiet study area, and giving kids with ADHD tape recorders and computers to track their chores and assignments. Sam works off excessive energy through sports--soccer, basketball, and track. "Exercise wears me out, and then I'm not so hyper in class," he says.

What's important is that kids with ADHD get counseling and medication personalized to their needs, explains Christ: "The important thing to remember is that ADHD is very treatable. Kids used to be made fun of for wearing glasses--now we have contacts.

Medicine works the same way. If there is a treatment that works, take it."

Q. How do we know that certain brain areas are involved in ADHD?

Actually, little research has been performed on teen brains. Some testing methods, while safe for adults, may be overwhelming to kids. For example, in positron emission tomography, or PET scans, a needle injects radioactive oxygen into a patient's arm vein. While the technique lets experts detect blood flow through different brain regions (see image, below)--a measure of brain activity--it can be scary.

But occasionally young subjects brave a procedure to help advance scientific understanding. One PET study of 300 boys and girls ages 5 to 18 by NIMH indicates the prefrontal cortex and basal ganglia may be smaller in people with ADHD, though it's unclear why.

In another breakthrough study, adult men with and without ADHD were asked to solve math problems. Those without ADHD showed increased activity in brain regions usually associated with memory and attention. But those with ADHD used the occipital region of the brain--which is linked to visual processing. In other words, the brains of ADHD subjects may work less efficiently in such tasks, says study chief Julie Schweitzer, a neuroscientist (brain scientist) at the Maryland Psychiatric Research Center. "Certain structures in the brain aren't accessible to people with ADHD. The brain needs to find other ways to get the job done."

Q. Can you outgrow ADHD?

Most people do not outgrow ADHD, but many, like Sam, learn to live fulfilling lives by developing coping skills--like learning to write down important details, or exercising, for example. People with ADHD tend to succeed in careers that call for them to be outgoing, such as sales and public speaking, or the arts, which calls for the creative ability to think of many things at once. "Having ADHD doesn't limit any career horizon," says Resnick, who cites a neurosurgeon with ADHD. "He's able to stay on his feet in the operating room for hours."

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ADHD AND THE BRAIN

In the past several years, scientists
have linked three brain regions to
ADHD, and have begun to understand
how and why these function differently.

PREFRONTAL CORTEX

Forebrain area controls
judgment and thought
processes

BASAL GANGLIA

Cell clusters
coordinate
motor skills,
like limb
movement

OCCIPITAL REGION

Brain areas
linked to
vision and language

HYPER DIAGNOSIS?

"ADHD is the most diagnosed pediatric disorder in this country," says Robert Moyzis, a geneticist at the University of California, Irvine. "But we also believe that about two thirds of diagnosed kids don't have it according to strict testing criteria. Much of the time they have another condition, like severe depression or a learning disorder."

GENDER GAP: Boys are diagnosed with ADHD three time more than girls, according to the Centers for Disease Control, although learning disorders equally affect the genders.

SMART MEDICINE?

Stimulant drugs like Ritalin are the most common form of ADHD treatment.

See the Teacher's Edition for additional resources on ADHD.