Brain imaging studies show that the brains of those with ADHD are different from those without ADHD in terms of size, activity, and development. Certain regions of the ADHD brain can be as much as 10% smaller than those without ADHD. And areas such as the frontal lobes, cerebellum, and anterior cingulate, can be very under-active compared to normal. These areas can also be as much as two to three years behind in development compared to normal. These differences will remain through the life of a person with ADHD.
ADHD impacts various systems of the brain, particularly systems involved with "executive functions", "inhibition", and "working memory". Most of these involve the activity of the frontal lobes, and the interaction of the frontal lobes with other structures of the brain acting as a "system". But since the frontal lobes are smaller, less active, and behind in development, each of these systems is impacted to some degree. As other areas of the brain are also affected, the look or type of ADHD is different.
Many studies are looking at how the ADHD brain matures in children and teens, and how it matures differently than someone without ADHD. We have discussed this at the ADHD Information Library considering both brain development in children, and in teenagers. One recent study funded by the National Institutes of Health and led by Dr. Philip Shaw considered this important issue. Their research is published in Biological Psychiatry.
It is estimated that about 9% of all children have ADHD. Of children referred to mental health professionals, more are referred for ADHD than for any other condition. But ADHD is also one of the most treatable of all psychiatric disorders, with several effective options ranging from medications to alternative therapies, psycho-social treatments, and educational interventions. Those with ADHD can have problems in many of the areas of their life, including home, school, work, and in relationships. ADHD is a chronic and unrelenting problem. Though it will change in form through the years, it will persist into adulthood and impact all relationships including marriages, parenting, and work performance. While there are different types of ADHD, depending on the different areas of the brain that are impacted most, there are commonalities that everyone with ADHD will contend with. No matter the types of ADHD, there will be at least some degree of Inattention; some degree of frontal lobe involvement; some degree of working memory deficits and executive function impairment; some problems at school; and some degree of delayed brain development.
Here's a good resource developed by some researchers at Harvard to help improve working memory. Its a computer based program to improve working memory in children and teenagers.
ADHD brain maturation delay
(Video, MP4 File)
In this particular study 230 kids with ADHD and 230 kids seemingly without ADHD underwent a series of brain scans to measure both the thickness of the brain cortex and the cortical surface area. The subjects without the ADHD were used as a control group. The children were first scanned at about the age of 10, and then again about every two years ending by age 17. Using the latest brain imaging tools the research team mapped the surface area development across the brain. Their study was consistent with other recent studies, that the brain development in the frontal lobes is delayed in those with ADHD. The brain maturity or development, in terms of size and surface area, is about two years behind the development in non-ADHD children and teenagers.