Ninety percent of adolescents with moderate to severe Attention Deficit Hyperactivity Disorder (ADHD) continue to suffer from severe to profound symptoms and impairments long after their diagnosis; and in many cases, the treatments they receive have little effect. A study from the Journal of the American Academy of Child and Adolescent Psychiatry shows that. The study was a collaborative effort funded by the federal government and led by researchers at Johns Hopkins University. The project is also the largest long-term study of ADHD in preschoolers to date and sheds some light on the condition, which is now being diagnosed earlier and earlier. Dr. Mark Riddle of the Johns Hopkins University Children’s Center, the project’s principal investigator, said, “The diagnosis of pediatric ADHD has become increasingly common in younger children, making it critical to study how the disorder develops in this age group. We have found that in preschoolers, ADHD is a chronic and fairly persistent condition; the disorder requires long-term behavioral and medication treatments for which our current tools are still inadequate.” Nearly 90 percent of the 186 children tracked continued to suffer from ADHD symptoms six years after diagnosis. The severity of symptoms remained similar in children who received ADHD medication compared to those who did not.