Do you ever lose focus after working for several hours on a project? Are there times when you just can't seem to concentrate anymore? If you answered yes to these questions then you are probably normal. But what is normal? And for that matter what is attention deficit "hyperactivity" disorder, ADHD? According to the DSM, there are sixteen behavioral differences between the two groups.

In a recent Harvard study claimed that ADHD costs Americans suffering from the condition about $77 billion in lost income a year, more than the total costs of drug abuse or depression. Usually considered a childhood disorder, ADHD affects about 8 million U.S. adults and is linked to job loss, lower income, higher divorce rates and more driving accidents, said Dr. Joseph Biederman, professor of psychiatry at Harvard Medical School.

To help understand how the current set of attention focusing cogniceuticals impact normal brains versus those with ADHD, the NIMH recently approved a study that would give normal children and children with ADHD dextromethylphenadate and use neuroimaging techniques to see if there is a different response.

Since there are currently no biomarkers or neuroimaging tests that define ADHD from a neurological perspective, some argue that it doesn't exist. This new trial would add magnetic resonance images to map any differences in brain activation patterns, even though previous studies that attempted to use neuroimaging to define the disorder remain controversial.

While giving normal children these performance focusing cogniceuticals is causing a bit of an ethical stir, Judith Rapoport, chief of child psychology at NIMH, conducted a similar trial 20 years ago. The same stimulant was given to children at a higher dose. Researchers looked only at how the stimulant changed children's behavior as they performed tasks. The stimulant improved attention span in the children, regardless of whether they had ADHD. This time, I guess we'll see where specifically there might be a difference in brain activation between the groups and see if we can make a dent in this profoundly disruptive problem.