Posted on 11/12/2007 2:19:05 PM PST by crazyshrink
In youth with attention deficit hyperactivity disorder (ADHD), the brain matures in a normal pattern but is delayed three years in some regions, on average, compared to youth without the disorder, an imaging study by researchers at the National Institutes of Health’s (NIH) National Institute of Mental Health (NIMH) has revealed. The delay in ADHD was most prominent in regions at the front of the brain’s outer mantle (cortex), important for the ability to control thinking, attention and planning. Otherwise, both groups showed a similar back-to-front wave of brain maturation with different areas peaking in thickness at different times.
“Finding a normal pattern of cortex maturation, albeit delayed, in children with ADHD should be reassuring to families and could help to explain why many youth eventually seem to grow out of the disorder,” explained Philip Shaw, M.D., NIMH Child Psychiatry Branch, who led research team.
Previous brain imaging studies failed to detect the developmental lag because they focused on the size of the relatively large lobes of the brain. The sharp differences emerged only after a new image analysis technique allowed the researchers to pinpoint the thickening and thinning of thousands of cortex sites in hundreds of children and teens, with and without the disorder.
“If you’re just looking at the lobes, you have only four measures instead of 40,000,” explained Shaw. “You don’t pick up the focal, regional changes where this delay is most marked.”
Among 223 youth with ADHD, half of 40,000 cortex sites attained peak thickness at an average age of 10.5, compared to age 7.5 in a matched group of youth without the disorder.
Shaw, Judith Rapoport, M.D., of the NIMH Child Psychiatry Branch, Alan Evans, M.D., of McGill University, and colleagues report on their magnetic resonance imaging (MRI) study during the week of November 12, 2007, in the online edition of the Proceedings of the National Academy of Sciences.
The researchers scanned most of the 446 participants – ranging from preschoolers to young adults – at least twice at about three-year intervals. They focused on the age when cortex thickening during childhood gives way to thinning following puberty, as unused neural connections are pruned for optimal efficiency during the teen years.
In both ADHD and control groups, sensory processing and motor control areas at the back and top of the brain peaked in thickness earlier in childhood, while the frontal cortex areas responsible for higher-order executive control functions peaked later, during the teen years. These frontal areas support the ability to suppress inappropriate actions and thoughts, focus attention, remember things from moment to moment, work for reward, and control movement – functions often disturbed in people with ADHD.
Circuitry in the frontal and temporal (at the side of the brain) areas that integrate information from the sensory areas with the higher-order functions showed the greatest maturational delay in youth with ADHD. For example, one of the last areas to mature, the middle of the prefrontal cortex, lagged five years in those with the disorder.
The motor cortex emerged as the only area that matured faster than normal in the youth with ADHD, in contrast to the late-maturing frontal cortex areas that direct it. This mismatch might account for the restlessness and fidgety symptoms common among those with the disorder, the researchers suggested.
They also noted that the delayed pattern of maturation observed in ADHD is the opposite of that seen in other developmental brain disorders like autism, in which the volume of brain structures peak at a much earlier-than-normal age.
The findings support the theory that ADHD results from a delay in cortex maturation. In future studies, the researchers hope to find genetic underpinnings of the delay and ways of boosting processes of recovery from the disorder.
“Brain imaging is still not ready for use as a diagnostic tool in ADHD,” noted Shaw. “Although the delay in cortex development was marked, it could only be detected when a very large number of children with the disorder were included. It is not yet possible to detect such delay from the brain scans of just one individual. The diagnosis of ADHD remains clinical, based on taking a history from the child, the family and teachers.”
### Also participating in the research were: Kristen Eskstrand, Wendy Sharp, Jonathan Blumenthal, Dede Greenstein, Liv Clasen, and Jay Giedd, M.D., NIMH.
The National Institute of Mental Health (NIMH) mission is to reduce the burden of mental and behavioral disorders through research on mind, brain, and behavior. More information is available at the NIMH website, http://www.nimh.nih.gov.
The National Institutes of Health (NIH) - The Nation's Medical Research Agency - includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical, and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.
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I’m a fan of Peter Breggin and the like, ever since my kid’s elementary school tried to force me to put my kid on Ritalin.
I held them off but it wasn’t pretty, and they had no problem blaming every grade she received under an A (not too many of them) on the need for Ritalin. At one point they told me they’d deny her entry into an advanced reading class unless I had an IEP for her - that ploy didn’t work, but they made her life miserable that year because of it. It’s the main reason we started homeschooling - then we continued homeschooling because we loved it.
Sorry, but in many ways I despise most members of your profession. You sound like one of the good ones, like Breggin.
LOL
My kid too. He did miserably in a private school, even worse in a public school.
Our years home teaching him have seen his learning curve soar! He was learning Algebra II and reading and comphrehending on a college level at age 14, just 26 months after having failed 6th grade. All it took was 9 months in high school and we were back to home schooling.
He will be taking his GED in about a year so he can go on and do what he wants rather than languishing in high school. His retention ability has increased greatly, and we don’t really know why. This article has perhaps given us a clue. Our family members have always been late developers, and know I may have a clue as to why that is so.
Our kids are similar. I pulled mine out in 6th grade, which was 6 years ago, and mine is now pulling As in community college.
That is super! Mine is making his way there too.
CC is great. It really builds their confidence and saves money at the same time. :)
Disease and disorder are not the same. I was among the skeptics of ADHD, and one of those who believed if the parent would just apply the board of education to their seat of knowledge they could cure the kid. My 6-year old son most definitely has ADHD. I have been working with him at home with that Total Transformation program that you hear advertised on the radio, and it does seem to have helped at home - but at school I have been pulled aside by the teacher 3 times to tell me is is not listening to simple directions in class. A typical incident would be her giving directions for the students to grab a pencil and eraser and gather in a circle on the mat. He will join the other kids on the mat, but be the only one who did not grab the pencil and eraser. I’m at Witt's end, and I don’t believe in giving them drugs, unless they are a danger to them selves or others.
Disease and disorder are not the same.
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We agree. IMHO, ADHD is a slight biologicial anomaly, not a disease.
I have heard of, but am not familiar with, the info you are talking about. With the families I work with, helping them to learn how to break down a large task into smaller ones is often a huge success. ADHD behavior often leaves the person feeling “overwhelmed”.
Break the task into smaller ones. One example I frequently use is cleaning your room. An ADHD behaviored person may see that as overwhelming and not know where to start. By breaking it into smalll tasks, say like this:
1) pick up all dirty clothes and put in hamper
2) pick up toys and put in toybox
3) make bed
etc. etc.
It sounds like your child was caught in the high stimulus moment of all his/her classmates suddenly moving around. A good teacher, who is aware of ADHD, could cover your child’s “forgetting” the pencil etc. quite easily w/o embarassing him/her. Assign a classmate to help, look specifically at him/her when speaking, etc. etc.
It is not that he isn’t listening!!! His executive functioning hasn’t developed fully yet. IMO, this is no different than other children who may be shorter or taller or whatever than the rest of the children.
Hang in there. You sound like you are on the right track. Keep up the research. There are tons of materials available for families as well as teachers. If you need some help, you have my freepmail.
Ben
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