Article human 29 female 27 male 27 major clinical study 21 attention deficit disorder 20 Humans 19 controlled study 19 child 16 Attention Deficit Disorder with Hyperactivity 15 Male 15 Female 13 adolescent 13 attention deficit hyperactivity disorder 13 Child 12 ADHD 10 adult 10 psychology 8 school child 7 Adolescent 6 anxiety disorder 6 attention 6 United States 5 central stimulant agent 5 comparative study 5 executive function 5 methylphenidate 5 physiology 5 priority journal 5 Attention 4