I posted the NIMH URL earlier. Here is a press release from NIMH about
the more recent study.
Subtle Brain Circuit Abnormalities Confirmed in ADHD
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Subtle structural abnormalities in the brain circuit that inhibits
thoughts have been confirmed in the first comprehensive brain imaging
study of Attention Deficit Hyperactivity Disorder (ADHD). Difficulty
staying mentally focused is a primary symptom of ADHD, which affects
about 5 percent of school age children. Magnetic Resonance Imaging (MRI)
scans of 57 boys with ADHD, aged 5-18, also revealed that their brains
were more symmetrical than those of 55 age-matched controls. F. Xavier
Castellanos, M.D., of the National Institute of Mental Health and
colleagues report on their findings in the July issue of the Archives of
General Psychiatry.
Three structures in the affected circuit on the right side of the brain
-- prefrontal cortex, caudate nucleus and globus pallidus -- were
smaller than normal in the boys with ADHD, when examined as a group. The
prefrontal cortex, located in the frontal lobe just behind the forehead,
is believed to serve as the brain's command center. The caudate nucleus
and globus pallidus, located near the middle of the brain, translate the
commands into action. "If the prefrontal cortex is the steering wheel,
the caudate and globus are the accelerator and brakes," explained
Castellanos. "And it's this braking or inhibitory function that is
likely impaired in ADHD." ADHD is thought to be rooted in an inability
to inhibit thoughts. Finding smaller right hemisphere brain structures
responsible for such "executive" functions strengthens support for this
hypothesis.
The NIMH researchers also found that the entire right cerebral
hemispheres in boys with ADHD were, on average, 5.2% smaller than those
of controls. The right side of the brain is normally larger than the
left. Hence, the ADHD children, as a group, had abnormally symmetrical
brains.
Although the same brain circuit had been implicated earlier, Castellanos
and colleagues examined a dozen times more brain areas in a three-fold
larger sample than had been studied previously.
"These subtle differences, discernible when comparing group data, hold
promise as telltale markers for future family, genetic and treatment
studies of ADHD," said Judith Rapoport, M.D., senior author on the paper
and chief of the NIMH Child Psychiatry Branch. "However, because of
normal genetic variation in brain structure, MRI scans cannot be used to
definitively diagnose the disorder in any given individual."
The newly confirmed markers may provide clues about the causes of ADHD.
The investigators found a significant correlation between decreased
normal asymmetry of the caudate nucleus and histories of prenatal,
perinatal and birth complications, leading them to speculate that events
in the womb may affect the normal development of brain asymmetry and may
underlie ADHD. Since there is evidence for a genetic component in at
least some cases of ADHD, factors such as a predisposition to prenatal
viral infections could be involved, said Dr. Rapoport.
The NIMH researchers are currently following up on a recent discovery of
a link between ADHD and a gene variant known to code for a particular
receptor subtype for the neurotransmitter dopamine. "We want to see the
extent to which children with this gene variant also have the brain
structural abnormalities revealed in this study," said Dr. Castellanos.
The researchers are currently extending confirmation of the markers in
girls as well as boys who have not been exposed to medication. They are
also using functional MRI scanning to visualize brain activity in ADHD.
Other NIMH researchers participating in the study were: Jay Giedd, M.D.,
Wendy Marsh, Susan Hamburger, Catherine Vaituzis, Yolanda Vauss, Debra
Kaysen, Amy Krain, Gail Ritchie, and Jagath Rajapakse. Also
participating were: Daniel Dickstein, Brown, U.; Stacey Sarfatti, U. Of
Pennsylvania; John Snell, Ph.D., U. Of Virginia; and Nicholas Lange,
Ph.D., National Institute of Neurological Disorders and Stroke.
The National Institute of Mental Health is a component of the NIH, an
agency of the U.S. Public Health Service, part of the U.S. Department of
Health and Human Services.
______________________________________________________________________
Jane, this is called real research. BTW, Dr. Terry Neher was the
developer of something that is now called Restores. It is sold by multi-
level marketers who are not known for their affinity for the truth.
Oh, and the "study" (regarding using Restores for ADHD) that Neher
started was never accepted for publication by any peer reviewed journal.
The problem with it was that he dropped those kids from the study who
got worse on Restores. That is always a problem when the manufacturer is
buying the testing.
Note, I make no comment about Restores and its use in treating
alcoholics. They probably are malnourished and Restores can do them a
world of good.
The Few. The Proud. The Chosen.
markprobe@aol.com
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