1) The neurobiological nature of ADHD.....THE PROOF YOU SAY DOESNT EXIST: was conclusively proven in the 1990 landmark glucose brainscan research study published in the New England Journal of Medicine....
Zametkin,A.J.,Nordahl,T.E.,Gross,M.,King,A.K.,Semp le,W.E.,Rumsey,J.,Hamburger,S.,& Cohen,R.M.(1990) Cerebral glucose metabolism in adults with hyperactivity of childhood onset. The New England Journal of Medicine,323,(30).1361-1366.
The "proof" is in the PET scans that showed that the harder a person with ADHD concentrated the "slower" their brain went vs the exact opposite for the non ADHD group. However, that was remedied when the ADHD subjects took stimulant medication.
THE definitive study proving the existence of ADHD as a "real" disorder;signed off on by over 80 of the world's leading scientists (with over 19 pages of references) is :
Consortium of international scientists:International Consensus Statement on ADHD, January 2002. (
http://www.chadd.org). It can also be viewed at Russell Barkley's website.
You can turn to pages 22-24 of Sandra Rief's 2003 book.............The ADHD Book of Lists ....................to find the section (1-7) WHAT THE RESEARCH IS REVEALING ABOUT ADHD
Within that section is the reference for the Landmark MTA Study:
"There has been significant research with regards to treatments for ADHD and their relative effectiveness. The longest and most thorough study of the effects of ADHD interventions was the 1999 Multimodal Treatment Study of Children with ADHD (MTA) by the National Institute of Mental Health (NIMH).
MTA Cooperative Group" A 14-month Randomized Clinincal Trial of Treatment Strategies for AD/HD,"[i]Archives of General Psychiatry, 56:1073-1086;1999.
ADHD is primarily thought to be largely (80%) genetic/inherited.THE GENETIC LANDMARK FOR ADHD WAS FOUND IN 995. That study is as follows:
Cook,et.al.,(1995) Association of attention-deficit disorder and the dopamine transporter gene.American Journal of Human Genetics,56.993-998.
The US Surgeon General's Report on Mental Health: Chapter 3: Disorders of Infancy, Childhood & Adolescence has excellent background info supporting in great detail (with another 19 pages of scientific references).Here's a small segment on what I'm talking about
:
" The exact etiology of ADHD is unknown,although neurotransmitter deficits,genetics and perinatal complications have been implicated." It goes on to say:
"Research to pinpoint abnormal genes is honing in on 2 genes;a dopamine receptor gene (DRD) gene on chromosome 11 and the dopamine -transporter gene (DAT1) on chromosome 5 (Cook,et.al.,1995:Smalley,et.al.;1998).
The latter reference is : Smalley,et.at.(1998) Evidence that the dopamine D4 receptor is a succeptibility gene in attention-deficit hyperactivity disorder,Molecular Psychiatry,3,427-430.
Recently (3/25/05), I participated in a teleconference on ADHD in children put on by United Behavioral Health (UBH: a managed care company). The presenter was Russell Barkley, PhD. He is largely viewed as the world's leading researcher on ADHD. During that presentation, he listed the following (evidenced based/research derived) data regarding the neurology of ADHD.
Decreased Cerebral Metabolism
(from Thomas Spencer, M.D.)
global and regional glucose metabolism by PET scan reduced in adults who have been hyper since childhood (thats Zametkin's research again).
Largest reductions in:
1) pre motor cortex
2) superior prefrontal cortex
Anterior Cingulate Dysfunction in ADHD, fMRI and the Counting Stroop.
Bush,et.al.,(1998).
Etiologies-Neurological
Smaller, less active,less developed brain
Regions found on MRI,fMRI and PET scans incluse the following areas of the brain:
1) Orbital-Prefrontal Cortex( primarily on the right side)
2) Basal Ganglia (mainly striatum and globus pallidus)
3) Cerebellum (central vermis area, right side) - there were some other posts about this particualr area of the brain being a key component of ADHD in a different thread I believe
Suspected Neurochemical Deficiency:
1) Dopamine dysregulation likely but not definitive....... the mere fact that stimulant
medication works at all to relieve symptoms of ADHD forms a solid basis
for helping to substantiate this (and the first medication study was done in 1937 in
Rhode Island)
2) Norepinephrine dysregulation probable
Etiologies- Genetic ( these data were all derived from research studies) The usual maker for statistical significance is 1.5 SD (standard deviation) 's from the mean, which equates to a %tile ranking of 93. In other words, the absolute lowest chance of these data being accurate is 93%.
1) Family aggregation of the disorder: 25-35% of siblings; 78-92% of idnetical twins;15-20% of mothers, and 25-30% of fathers; If the parent is ADHD, then theres a 20-54% chance of the offspring being ADHD (increases the odds 8fold)
2) Twin studies of Heritability 57-97%)
3) Shared environment 0-6% (not significant)
4) Unique environment (15-20% )
Molecular Genetics : Candidate genes on DRD4,DAT1,DBH-Taq1 (on chromosomes 3,5,and 11)
Candidate region: chromosome 26p13 region
Lastly, the answer to your questions about the difference between ADHD and ADD can be found in Barkley's ADHD and the Nature of Self-Control (1997).
It's also addressed in his 2002 book Taking Charge of ADHD (pages 137-138) and in You Mean Im Not Lazy,Stupid Or Crazy? by Kate Kelly & Peg Ramundo (Chapter 2).
As for depression, it is considered to be a Medical disorder on the basis of the chemical imbalance of the neurotransmitter serotonin. I don't know anyone who considers it to be a "disease".
There's no cure for the common cold but people know it exists. The Biogenic Amine Hypothesis was derived (via research) over 20 years ago. Here's what that says: "The concept that abnormalities in the physiology and metabolism of certain biogenic amines, particularly catecholamines[i](norepinephrine and dopamine ) and an indoleamine(serotonin) , are involved in the causes and courses of certain psychiatric illnesses."
That qoute was from an older issue of A Psychiatric Glossary of the AMerican Psychiatric Association, page 28. The new one is at the office.
The Biogenic Amine Hypothesis is what eventually led to the development of the class of antidepressants we now know as SSRI's (Select Serotonin Reuptake Inhibitor's:Zoloft, Prozaz,etc.).
This MORE than refutes your remarks. As of the summer of 2003 there were over 6k research articles,professional papers, chapters in book and books on ADHD.
If you go to the International Consensus 2002 journal article, you will also find on page 89:
"ADHD is recognized as a disorder/medical condition by the American Medical Association, the American Psychiatric Association, the American Psychological Association and the American Academy of Pediatrics."
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Originally Posted by MR_T
