From 2000 to 2010, US children and teens diagnosed with attention-deficit hyperactivity disorder jumped from 6.2 million to 10.4 million, researchers say. Dr. Craig Garfield of Northwestern University\'s Feinberg School of Medicine and a pediatrician at Children\'s Memorial Hospital and Northwestern Memorial Hospital said the 66 percent increase in physician-diagnosed ADHD cases in the past decade means it is now \"a common diagnosis among children and teens.\" The 2010 Census found there are about 75 million Americans under age 18. \"The magnitude and speed of this shift in one decade is likely due to an increased awareness of ADHD, which may have caused more physicians to recognize symptoms and diagnose the disorder,\" Garfield, the first author of the study, said in a statement. Symptoms of ADHD, such as trouble paying attention and controlling impulsive behaviors and being overly active, can affect children and teens both academically and socially, Garfield said. Garfield and his team quantified ADHD diagnosis and treatment for those age 18 and under using the IMS Health National Disease and Therapeutic Index via a nationally representative sample of office-based visits and included 4,300 office-based physicians in 2010. They found that more diagnoses are being made by specialists rather than primary doctors. They also learned psychostimulants were used in 96 percent of treatments in 2000 and 87 percent in 2010. Garfield said the exact reason for the decrease is unclear. The researchers\' findings are to be published in the March/April issue of the journal Academic Pediatrics.