[Sasha]

I thought this was interesting and has to have implications for us with Parkinson's, right? Or not? Has anyone ever taken Ritalin?


Brain Studies Show ADHD Is Real Disease
By Steven Reinberg, HealthDay Reporter
HealthDay

MONDAY, Aug. 6 (HealthDay News) -- Attention-deficit/hyperactivity disorder (ADHD) is a real disease linked to changes in production of the brain chemical dopamine, two new reports suggest.In the first report, researchers found that a variant of the dopamine receptor gene may help cause the behavioral condition but also improve its long-term outcome."If you have a certain variant of this gene, you have a greatly increased risk of having ADHD," said lead researcher Dr. Philip Shaw...... In addition, 67 of the children with ADHD were evaluated six years later.Shaw's team found that a variant in the dopamine D4 receptor gene (DRD4) was associated with ADHD......."This is a very important study as it adds increasing evidence that ADHD is a heritable disease with genetically determined neurobiological underpinnings and adds further evidence that this is a valid mental disorder, often requiring neurobiological interventions [such as] psychopharmacological treatment," said Dr. Jon A. Shaw, professor and director of child and adolescent psychiatry at the University of Miami Miller School of Medicine.A second study -- led this time by Dr. Nora D. Volkow, director of the U.S. National Institute on Drug Abuse -- suggests that the ADHD drug Ritalin works by increasing the brain's production of dopamine.This finding implies that reduced production of dopamine is involved in ADHD and may help explain why many people with the condition also abuse drugs."Individuals with ADHD have a decreased function of the brain dopamine system," Volkow said. "ADHD, clearly, is associated with a biochemical dysfunction," she added.The finding is important, because it belies the myth that ADHD is not a real disease but was just created "to sell medication," Volkow said. Instead, "this finding explains why stimulant medications, such as Ritalin, are beneficial, because they increase dopamine function in the brain," she said.In the study, Volkow's team performed brain scans of 19 adults with ADHD who had never received Ritalin, as well as 24 healthy individuals. The scans were done after the participants were given shots of Ritalin or placebo.The team found that the people with ADHD released less dopamine into their blood than those without the disease. However, Ritalin caused less of a decrease in dopamine than usual in these individuals. This reduction in dopamine was associated with typical symptoms of inattention, the researchers found.Volkow noted that drugs such as nicotine, cocaine and methamphetamine also improve dopamine brain function."This may be the reason why individuals that have ADHD are at a much greater risk of abusing substances than the general population, because drugs of abuse increase dopamine brain function, and they will 'feel better,' " Volkow said.More informationFor more on ADHD, visit the U.S. National Institute of Mental Health.
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URL: http://health.msn.com/centers/adhd/a...ntid=100167398

(I added the bolding and edited out a bit, as indicated by ......)