What could be working is the dopamine-promoting properties, not the stimulant effect of Ritalin. He added this might show ADHD is caused by not enough dopamine in the brain.
Dopamine is a neurotransmitter, or message-carrying chemical, that is involved in movement.
The two drugs in the study, L-Dopa and pergolide, are commonly used for people with Parkinson's disease, who lack dopamine. The research could also help explain why Ritalin, a common drug for treating ADHD, improves hyperactive behavior, said Arthur Walters, a neurologist at the Robert Wood Johnson Medical Center. What could be working is the dopamine-promoting properties, not the stimulant effect of Ritalin. But because Ritalin is a stimulant that works on the central nervous system, many people are concerned about addiction and the drug's possible side affects, Walters said. A goal of the research would be to create an alternative treatment to Ritalin, known generically as methylphenidate.