McLean Hospital researcher Martin Teicher and his team believe that the surest way to separate youngsters who have attention deficit hyperactivity disorder (ADHD) from those with other problems is to look at their brain activity. His team 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. 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. This research has led to development of tests for ADHD which have been licensed for commercial use.