Brain shrinkage in ADHD not caused by m...( 100 networked computer workstations d...),Health

While the NIMH group had earlier thought that only certain brain structures were smaller in ADHD, this largest and most sophisticated study found that the whole brain is affected. It's possible that a recently discovered gene that determines brain size could play a role in the disorder, Castellanos suggested. He also suspects that what is now called ADHD may ultimately prove to be a group of disorders with different causes. To identify these subtypes, he suggests that the field begin studying "endophenotypes," factors that may predict the risk of ADHD in the same way that cholesterol predicts the risk of heart disease.

"MRI remains a research tool and cannot be used to diagnose ADHD in any given child, due to normal genetic variation in brain structure," noted Rapoport. "The measured influence of ADHD on brain volume can only be discerned statistically across groups of children with and without the disorder."

Also participating in the research were: Drs. Patti Lee, Deanna Greenstein, Liv Clasen, Regina James, Jay Giedd, and Wendy Sharp, Christen Ebens, Jonathan Blumenthal, James Walter, NIMH Child Psychiatry Branch; Dr. Neal Jeffries, National Institute of Neurological Disorders and Stroke (NINDS); Drs. Alex Zijdenbos, Alan Evans, MNI, McGill University.

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Contact: Jules Asher
NIMHpress@mail.nih.gov
301-443-4536
NIH/National Institute of Mental Health
8-Oct-2002