There are several treatment options available to help improve the symptoms of Attention Deficit Hyperactivity Disorder. Since there is no prescription medicine that can "cure" for ADHD, the various medical interventions seek to improve symptoms. The most commonly used medicines are stimulants, such as Ritalin, Dexedrine, Cylert, and ADDerall. Stimulants have been around for about 50 years. Overall, they work very well. Ritalin and Dexedrine are moderately beneficial, or very beneficial, for about 70% to 75% of those who try them.

Stimulants work by increasing both blood flow and the levels of Dopamine in the brain, especially the frontal lobes where the brain's Executive Functions take place. They also increase the inhibitory systems of the brain by enhancing Serotonin and Norepinepherine levels. They do not work by having some mystical "opposite effect" on children.
There is an unbelievable amount of research done on children and Ritalin, less with Dexedrine, ADDerall, and Cylert. We have heard that Ritalin is the most widely studied medication prescribed to children in the world, and we would not dispute that claim. It seems that every doctoral candidate writing his dissertation for psychology does something with Ritalin.