Martin Teicher holds an actigraph, which is worn by children to record the number of movements they make each minute. Photo by Jon Chase.

Schoolchildren all over the country are fidgeting too much, not paying attention, and disrupting other students. In some schools, as many as one in every 10 children is labeled as hyperactive, having an attention disorder, or both. But not all teachers and experts agree about the extent of the problem, or the wisdom of treating these youngsters with drugs.

"If a child behaves like we expect someone with attention deficit hyperactivity disorder (ADHD) to behave, we label the child with that disorder, then treat him or her with medication," notes Martin Teicher, associate professor of psychiatry at Harvard Medical School. "That's not the ideal way to make a diagnosis. It fails to distinguish between children who have a diminished capacity to sit still and those who have the ability but fail to use it."

Other problems such as depression, post-traumatic stress disorder, and learning and conduct disorders, which a child can have in addition to, or instead of, ADHD, complicate the picture.

To increase accuracy and reliability, Teicher and his colleagues at Harvard-affiliated McLean Hospital in Belmont, Mass., carefully monitored the motions of thousands of children, including 700 first- and second-graders. They found that specific patterns of movement distinguish kids with ADHD from those who are normal, depressed, or suffering from traumatic stress disorder as a result of abuse.

This research has led to development of tests for ADHD which have been licensed for commercial use and are now being evaluated.

"Normal children never show up as abnormal on a so- called OPTAX test," Teicher notes. "On the other hand, not every child diagnosed with ADHD by current medical standards will show up as positive. We strongly suspect that these children have other disorders masquerading as ADHD, and these children often fail to benefit from medications given for the disorder. More children need to be tested to determine the strengths and limitations of this and other tests."

Sex Differences

Using OPTAX to record and analyze the movements of students on an attention test, Teicher and his colleagues found that boys with ADHD move two to three times as much and cover four times as much area as normal boys. Girls with ADHD move as frequently but their movements cover a smaller area.

OPTAX uses small, mirror-like devices placed on a child to reflect infrared light. The system records movements as small as two-thousandths of an inch and feeds 50 measurements a second into a computer for analysis. Qualisys Inc. makes the hardware, and Teicher wrote the software for recording and analysis.

ADHD is a serious disorder that not all children "outgrow." It persists beyond childhood in about 40 percent of cases. It's associated with a fivefold increased risk of drug abuse, ninefold of incarceration, tenfold of antisocial personality, and 25-fold of institutionalization for delinquency.

Boys are four to six times more likely to be treated for ADHD than girls, but among adults there is almost no difference between males and females who receive treatment. To investigate the discrepancy, Teicher's colleagues at McLean Hospital -- Carol Glod, Ann Polcari, and Cynthia McGreenery -- tested 700 elementary school students. They found that as many girls as boys had problems with attention. Their teachers, however, tended to exaggerate problems with boys and miss them in girls.

"We require girls to have the same number of symptoms as boys, and this leads to a large gap in diagnosis of ADHD," Teicher maintains. "Our findings suggest the gap may be closed by requiring fewer symptoms in girls."

Brain Scanning

Teicher and his team believe that the surest way to separate youngsters who have ADHD from those with other problems, or those who are turned off by school, is to look at their brain activity. Boys with and without ADHD underwent noninvasive brain scans (functional MRI) after taking the OPTAX test. The scans measure the amount of blood flowing to different parts of the brain.

The researchers found that a marked difference in flow to an area in the center of the brain called the putamen distinguishes ADHD kids from normal kids. The putamen is a brain region principally involved in motor activity and fine movements. The blood flow pattern in their brains also correlates strongly with activity and attention measurements made by the OPTAX test.

Some children diagnosed with ADHD using standard medical procedures performed well on this test and had normal levels of blood flow to the putamen. This indicates that OPTAX plus brain scanning is more accurate for determining whether a child has ADHD. However, brain imaging can't be used to screen all young people for the disorder because it is expensive and takes several hours for an expert to analyze the results. The infrared test is much cheaper and easier to use.

Teicher's test can also be used to evaluate the effectiveness of drugs used to treat ADHD. The drug of first choice first is Ritalin (methylphenidate). Children testing positive for ADHD can be retested a hour or two after taking the drug. If Ritalin works, their test scores should be normal or closer to it than before.

"Some children, however, don't respond to Ritalin or become worse," Teicher points out. "In those cases, we can try Dexedrine [dexamfetamine] the following day. This drug often increases attention and decreases restlessness when Ritalin fails. Overall, we've found the test very useful for quickly determining the right medication and correct dose to help children with ADHD."

Depression and Abuse

Teicher's group also uses a device called an actigraph to study motion. Slightly bigger than a wristwatch, it records the number of movements made each minute. Experiments show that this gadget easily distinguishes between children with ADHD and those suffering from depression. Depressed youngsters exhibit an abnormal lack of activity, rather than hyperactivity, as well as a disturbed daily biological rhythm. They often are abnormally inactive on the OPTAX test as well, and they do not show the same pattern of inattention as those with ADHD.

Teicher notes that signs of ADHD usually appear before age 7. While depression can occur at any age, it usually starts substantially later, often at 12 to 13.

Working with Carol Glod, Teicher has also investigated differences and similarities in the movements of children with ADHD and post-traumatic stress disorder caused by abuse. In that study, they used actigraphs to record trunk movements of children and wrist movements of adults both asleep and awake.

These investigations reveal that abused youngsters with post- traumatic stress are about 11 percent more active than normal children, while those with ADHD were about 25 percent more active than normal. Abused kids without PTSD show altered biological rhythms, such as long periods of low activity or periodic napping, nighttime awakenings, and shifts in times of going to bed and getting up.

"Abusive experiences can place infants and toddlers in grave danger and can lead to abject terror, powerlessness, and helplessness," Glod notes. "Children who experience trauma at a later age may be less prone to develop PTSD because the abuse poses less risk of extreme danger and because options exist for disclosure of abuse and removal from the abusive environment."

Sexual abuse causes its greatest impact between 13 and 15 years. "At younger ages, sexual assaults are more horrible, but increased awareness of the improperness of abusive acts can increase the amount of stress experienced," Teicher explains.

Results from brain scans indicate that early abuse has a deleterious effect on brain development. Such attacks often lead to dissassociative symptoms, like finding articles in the closet you don't recall buying, or finding yourself someplace when you have no idea how you got there.

Surprisingly, the Teicher team discovered that verbal abuse can be as potent as sexual or physical abuse for causing such brain anomalies. Further, being screamed at and ridiculed by a mother is more harmful than verbal aggression from a father.

Teicher believes that some abused children are inaccurately diagnosed as having ADHD. Symptoms of stress, anxiety, or depression may produce behavioral disturbances resembling ADHD. Motion tests can often distinguish between the two, thus reducing or eliminating the confusion.

"Computer-based measures of activity and attention, along with brain imaging," Teicher says, "hold enormous promise for more reliable diagnoses and for evaluation of the success of drugs and other treatments."