"These results suggest that dopamine transporter levels alone cannot account for the severity of symptoms of inattention in ADHD," said Nora Volkow, Director of the National Institute on Drug Abuse and the lead author of the study. Added Gene-Jack Wang, who led Brookhaven's role in the research, "It is clear from these results that clinical measures of dopamine transporters should not be used as a basis for a diagnosis of ADHD."
ADHD is the most frequently recognized psychiatric disorder in children, with some 3 million children younger than 18 currently receiving treatment in the U.S. Yet the mechanism underlying this disorder and its treatment are still poorly understood. One prominent theory of ADHD is that there is a dysfunction in brain circuits that depend on the neurotransmitter dopamine to modulate attention, motivation, and interest. If, for example, ADHD subjects have elevated levels of dopamine transporters ?proteins on dopamine-producing cells that take up excess dopamine ?they could end up with depleted dopamine levels and reduced motivation/attention.
Four independent studies have reported that ADHD subjects have higher than normal levels of dopamine transporters in a bra
Source:DOE/Brookhaven National Laboratory