The various childhood problems that are often subsumed under the heading of "hyperactivity" occur in various combinations and, apparently, for various reasons. The designation does not define a homogeneous group of children, does not consistently point to a common cause, and has treatment implications only In the sense that multiple simultaneous approaches must typically be considered. Stimulant drugs, which seem frequently to be used for control of so-called hyperactivity, are an inadequate treatment when used alone, have a number of poorly studied effects, some of which are apparently negative, and may obscure problems other than the hyperactivity itself, which then may be ignored. There is some evidence now available that classroom learning does not improve with drug treatment despite common assumptions to the contrary.
Rie HE. Hyperactivity in Children. Am J Dis Child. 1975;129(7):783-789. doi:10.1001/archpedi.1975.02120440009003