Attention deficit hyperactivity disorder was first diagnosed in children in 1902 by Sir George Still, a British pediatrician, according to Healthline. Still found that certain intelligent children were incapable of exerting behavioral self-control like normal children, and he described the condition as an abnormal defect.
The three major ADHD symptoms are hyperactivity, inattentiveness and impulsiveness, notes Healthline. Doctors frequently diagnose ADHD in boys about twice as often as in girls, and the average age of patients is 7 years old at the time doctors diagnose them. The American Psychiatric Association recognized the neurobehavioral condition as a mental disorder late in the 1960s and changed its name from Attention Deficit Disorder to ADHD in 1987. In 1955, the U.S. Food and Drug Administration approved methylphenidate, and as of 2015, doctors continue to prescribe the drug, marketed as Ritalin, to treat children with ADHD.