Structural Neurology and the Differences in the ADHD Brain

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Structural Neurology of Attention Deficit Hyperactivity Disorder - ADHD

The Structural Differences include studies with MRIs, PET scans, and SPECT scans. They show subtle structural differences in these regions of the ADHD brain:
adhd research on functional differences

  • prefrontal cortex - especially the smaller right anterior frontal cortex, and also less white matter in the right frontal lobes which cause problems with sustained or focused attention,
  • caudate nucleus - asymmetries which cause problems with self-control,
  • globus pallidus
  • right hemisphere - the studies show that the right hemisphere of the ADD ADHD brain is, on average, 5% smaller than the control groups.

They also show differences in blood flow in certain parts of the brain, as well as chemical abnormalities in Attention Deficit Disorder subjects.


Zametkin's studies are enlightening in the structural differences in the ADHD brain. Brain scan images produced by positron emision tomography (PET) show differences between an adult with Attention deficit Hyperactivity Disorder (ADHD) (right) and an adult free of ADHD (left).

Source:zametkin PET scan research on ADHD

Alan Zametkin, M.D.
Section on Clinical Brain Imaging
Laboratory of Cerebral Metabolism
Division of Intramural Research Programs, NIMH 1990

Zametkin AJ, Nordahl TE, Gross M, et al. Cerebral glucose metabolism in adults with hyperactivity of childhood onset. New England Journal of Medicine, 1990; 323(20): 1361-6.

Several studies are included in this section on the Structural differences in the ADHD brain.

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