Monday, December 17, 2007

Delayed maturation of the cortex in children with ADHD

From Shaw et al., a very straightforward study showing that normal thickness of the cerebral cortex develops more slowly in children with attention deficit hyperactivity disorder. This kind of finding makes it even more disturbing that ADHD continues to be pervasively over-diagnosed in children, who are then drugged with Ritalin when they should just be left alone to let things straighten out in their own good time.

There is controversy over the nature of the disturbance in brain development that underpins attention-deficit/hyperactivity disorder (ADHD). In particular, it is unclear whether the disorder results from a delay in brain maturation or whether it represents a complete deviation from the template of typical development. Using computational neuroanatomic techniques, we estimated cortical thickness at >40,000 cerebral points from 824 magnetic resonance scans acquired prospectively on 223 children with ADHD and 223 typically developing controls. With this sample size, we could define the growth trajectory of each cortical point, delineating a phase of childhood increase followed by adolescent decrease in cortical thickness (a quadratic growth model). From these trajectories, the age of attaining peak cortical thickness was derived and used as an index of cortical maturation. We found maturation to progress in a similar manner regionally in both children with and without ADHD, with primary sensory areas attaining peak cortical thickness before polymodal, high-order association areas. However, there was a marked delay in ADHD in attaining peak thickness throughout most of the cerebrum: the median age by which 50% of the cortical points attained peak thickness for this group was 10.5 years (SE 0.01), which was significantly later than the median age of 7.5 years (SE 0.02) for typically developing controls. The delay was most prominent in prefrontal regions important for control of cognitive processes including attention and motor planning. Neuroanatomic documentation of a delay in regional cortical maturation in ADHD has not been previously reported.

Figure - The age of attaining peak cortical thickness in children with ADHD compared with typically developing children. (A) dorsal view of the cortical regions where peak thickness was attained at each age (shown, ages 7–12) in ADHD (Upper) and typically developing controls (Lower). The darker colors indicate regions where a quadratic model was not appropriate (and thus a peak age could not be calculated), or the peak age was estimated to lie outside the age range covered. Both groups showed a similar sequence of the regions that attained peak thickness, but the ADHD group showed considerable delay in reaching this developmental marker. (B) Right lateral view of the cortical regions where peak thickness was attained at each age (shown, ages 7–13) in ADHD (Upper) and typically developing controls (Lower). Again, the delay in ADHD group in attaining peak cortical thickness is apparent.

6 comments:

Ronit Baras said...

it is amazing how many things you present to people and still, there are so many, that think that Ritalin is the only option.
I think "being" is not something educators, parents, doctors or researches study enough.
Why is there such a need to lable? does it make us feel better or what?
I do hope many people read this article and realise we can change without "forcing" kids to be different just because it is easy for adults to handle.
great article, thank you!

Ronit Baras
www.ronitbaras.com

Dan said...

Speaking as a "delayed maturer", I am sorry that my parents, teachers, fellow students, and fellow drivers,(among others) aren't around to tell you the effects ON THEM, of MY "being left alone to straigthen out in their own good time." Medicine was not available when my ADHD hijacked my life and lowered its quality. Along with the quality of life of those who had to endure my untreated presence. The next time you have a muscle ache or asthma attack, why don't you just leave IT alone to straighten out etc. etc. Our parents didn't have these medicines so (using your "logic") obviously you don't need them either. And if you don't think that ADHD causes pain, just ask other ADHD sufferers (like my relatives and teachers who suffered from my ADHD). As one "Ritalin kid" once said; "My Ritalin hasn't had any effect on me. But now that you mention it, it has made my parents and teachers much calmer."

Withholding inexpensive treatment that would ease pain is immoral and unethical. What your blog should have said is that new imaging technology now permits the "seeing" of the condition and the results of maturation, medication, etc. This is an important advance because it presents empirical evidence of a very real condition and assists those who attempting to treat it.

If you're not capable of contributing to the advancement of treatment and acheivement of cure, you should at least try to stay out of the way of those who are.

Deric said...

My reference was to inappropriate or over diagnosis, not to a case like yours. Whether I would leave a muscle ache or asthma attack to straighten itself out would depend on its severity and duration. I am referring to cases in which ritalin has been prescribed to curb normal childhood exuberance, for the benefit of the parents, not the children.

Deric said...

I'm appending as a comment this email I received from blog reader Tricia:
The research was never really there to support the diagnosis of ADHD. What
was evident was that we could objectively measure a group of children and
10% of them would exhibit the signs and symptoms what is referred to as
ADHD. Medicating children with Ritalin in order to make them more
manageable in school became the preferred treatment for around 10% of
nations children. This lead to a higher incidence of drug abuse among those
who had been medicated with amphetamines in their youth. It also enabled
those children who had been labeled to feel somehow defective in the eyes of
the world. It also contributed to the medication of this same group of
children with antidepressants that had not yet been studied on the
developing brain. Antidepressants were only studied in the mature brain.
You don't have to look far in the media to find a case of a young adult on
Ritalin or one of it's substitutes to find side effects of not only
psychosis but also suicide. Please visit Scientific American :Smart Kids
found to Undergo Delayed Brain Development. I find it interesting that
intelligent kid's brain also have delayed development in the cerebral
cortex. May be that our nation set out to medicate those children who
displayed signs of intelligence rather than signs of a disorder. What a
tragedy.

Anonymous said...

I found this blog while doing research. I think I bring a different perspective. My son is almost 7 and has had poor impulse control since he was a toddler. It has become more and more apparent that he may fit the profile of a child with ADD/ADHD. I have been working very hard to rule other possible culprits out of the picture. He has had near to perfect health, our family has implemented the Feingold diet, and I am still working on various behavioral conditioning methods. My son did see a psychiatrist who offered to perscribe medication after only a two hour assessment. She primarily suggested anti-depressents...not quite fitting in his case. I am noticing the nudge to place him on medication because everyday is a gamble. 50/50 on good and bad days behaviorally, additude wise, etc...etc... He seems slightly behind compared to his peers however he is receiving tutoring and I am in constant contact with his teacher. The idea of giving my child a drug to change his inherit reactions to his surroundings rather then trying to teach him is appalling. Although I understand completely that there can be varing degrees of severity in cases and some may need it more then others. However, it is beyong denial that our society is using drugs to treat symptoms instead of finding solutions to problems. To touch on one of the other posts I read...I personally fought with severe asthma through childhood. I was placed on medication and steroids. I was in and out of the hospital often and I feared for my life at a tender age. Yet it was an elementary school gym teacher of all people who helped me learn how to control my asthma. He repeatedly recommended that even though exercise induced my asthma that I should jog regularly, slowly working up to longer intervals-in order to stregthen my lungs. I tried it and after awhile I went off medication and to this day I know my own body enough to know when I need to work out more. When I need to take a break to prevent an attack. I keep an inhaler for extreme situations only. I found this new information regarding delayed maturation intriguing. If this is the case then hopefully we can find improved ways of diagnosing ADD/ADHD and treating. As for my son, I will try any natural avenue possible and I am even looking into a special school for children with ADD. One post mentioned how much work ADD/ADHD is to the parents and educators. It has been my experience that anything worth doing was challenging. Helping my son to grow up to be a healthy, mature, intelligent, and self-satisfied individual...priceless.

Diana Rutherford said...

Dear Anonymous I was Diagnosed at an incredibly early age with ADHD and took medication all my life until i became 18 and decided to take a different approach. it is cognitive behavioral therapy, and it has truly helped me, i am 26 now, and am no longer plagued by my symptoms. Find a good children's therapist and have your son see him once a week for at least an hour. Cognitive Begavioral Therapy, and keep at it, I still go to a therapist once a week and I Love what it has done for me! better to start younger, one must relearn how to think and behave when they have ADHD, they don't necessarily have to be medicated! theres too much of that going on, and especially in the 90s, i was a 90s child and it sucked to be medicated because my parents couldn't deal with me. and anti-depressants just made it worse!

hope this helped

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