DSM-IV diagnostic criteria  
Critique of DSM-IV Criteria in regard to decline of symptoms with age (Barkley, 1997)  
More recent material: Other Perspectives (Intro Page)  Neurological Model  
  Drug Reactions (Breggin)   Barkley's Model   


Editor's Note, December 26, 2011:
     I strongly urge the reader to obtain a copy of Anatomy of an Epidemic, by Robert Whitaker. It provides overwhelming evidence, citing many large studies done in the 
U. S. and other nations, that drug treatment for psychiatric disorders tends to worsen mental illness, and to turn brief, treatable episodes into chronic mental illness. 


January 2, 2002
I am adding some new material to the Turnertoys presentation on ADHD, focusing on the theories of Russel Barkeley, Professor of Neurology and Psychiatry at the University of Massachussetts Medical Center.  He takes pretty the opposite position to that of Peter Breggin (for whom I provide sources and links below). Breggin sees ADHD primarily as a normal response of children to the situations in which they find themselves, as well as a symptom of a society that finds it easier to control children chemically than try to understand why they behave as they do, and also a result of faulty and indescriminate diagnosis.  Barkley has elaborated a theory of ADHD as a neurophysiological deficit in children afflicted with it, and has defined the identifying symptoms in a formal, theoretical way. Below are my discoveries in the literature and my speculations as of a year ago.  

4/22/06: This material is now embarassingly out of date, pending addition of material already written.  Maybe you shouldn't read it. Check back in a month (year?) or two or three.
11/29/2009: I have found studies (in 2005-2008) while reading to prepare some other writing that indicate a very large effect of intrafamilial conflict on ADHD-like behaviors* in children.  I have also had a little experience treating children whose parents claimed that the kids were hyperactive, hard to control, and could not focus. The parents in each of these cases were separated and engaged in warfare with each other at long distance, using the children as proxies. When the parents were convinced to stop exposing their children to these conflicts, and aided in this by family members who acted as go-betweens, or in 2 cases, by learning to behave civilly in each other's presence and parent cooperatively, the change in the behavior of the affected kids was so rapid as to seem magical. 
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*Since it is unlikely that there is anything like a unitary and distinct syndrome of symptoms and causes that might be treated as a single diagnostic entity called "ADHD",  I have taken to referring to the "disorder" simply as ADHD-like behaviors. 
Click here for some new material

A Brief History  (Another perspective - new materials)
In the 1960's, some children were diagnosed as Hyperkinetic, Hyperactive, or as having Minimal Brain Disfunction. Symptoms were impulsivity, poor attention span, social difficulties, and excessive motor activity.  It was a rare diagnosis, and no scientist or clinician claimed to know the cause, although many suggestions were put forward. By the early 1970's, 100,000 to 200,000 children were diagnosed with some variant of this problem, and were being treated with drugs. Still, no one had any idea exactly what the disorder was. It was found that stimulant drugs such as methylphenidate (Ritalin, Concerta, and Metadate) or forms of amphetamine (Dexedrine and Adderall) could control the symptoms in a small minority of children.  Scientists admitted frankly that there was no agreement concerning causal factors, or even precise diagnostic criteria.  If the child responded well to medication, he had the disorder; if he responded poorly, he did not. Presenting symptoms were likely to be the same in either case.

By the mid-1980's, the cluster of symptoms was being officially referred to as ADHD, and diagnostic standards had been formalized in the American Psychiatric Association's (APA)  Diagnostic and Statistical Manual of Mental Disorders, 3rd ed. (DSM-III). In 1995, 10 to 12 pecent of all boys between the ages of 6 and 14 in the U.S. were diagnosed with ADHD and were being treated with Ritalin.  Presently, the diagnostic standards are those found in DSM-IV, published in 1994. 

The number of children diagnosed and treated for Attention Deficit Hyperactivity Disorder now stands at about 5 million, according to one estimate. A study in North Carolina found that 10% of children were receiving stimulant drugs at home or in school.  As many as 15% of boys between the ages of 6 and 14 in the U.S. have been diagnosed with ADHD and are receiving drug therapy.  The United States now consumes about 90% of world Ritalin production.  

Three variations of ADHD are diagnosed: Hyperactive-impulsive, affecting primarily boys; Inattentive, which includes a higher percentage of girls; and combined. 

The question has arisen concerning whether the use of prescribed stimulants predisposes kids to later drug abuse.  According to Dr. Peter Breggin, Director of the International Center for the study of Psychiatry and Psychology, Methylphenidate, amphetamine, and cocaine affect the same neurotransmitter systems, and so use of Ritalin and similar drugs may result in use of illegal stimulants.  Nadine Lambert has conducted research which showed that ADHD children medicated with stimulants are more likely to start using illegal drugs than are other children.  However, a study by Biedermans, Wilens, et al found that medication for ADHD reduced the likelihood of later substance abuse.  Letting young people speak for themselves in this matter (personal anecdotes from young acquaintances), it is quite clear that Ritalin, at least, has become a fashionable drug of abuse, although in some cases in a new and strangely disciplined fashion. An interesting article at a student-run website...

From November 16-18, 1998, the National Institutes of Health convened the Consensus Development Conference on Diagnosis and Treatment of Attention Deficit Hyperactivity Disorder. The Consensus Statement (28 sec @ 28k; worth reading!) concluded: 
*Although nothing is known regarding causes, ADHD is a real disorder. 
*Stimulants, when used in a clinically rigorous and conservative fashion, can, along with  psychosocial therapies (behavior modification, parent training) yield positive results, as measured in short-term studies.  
*Present treatments address only core symptoms, and do little to improve academic or social outcomes.
*Long-term assessment of the values of various treatments have not been made. 
*There is no data on treatment of the inattentive type of ADHD, which tends to affect more girls.
*Alternate treatments, ranging from dietary adjustments to biofeedback, have been tried with various results. (See article on this -  large file, 34 sec @ 28k)
*Since knowledge of causation is only speculative, there are no strategies for prevention. 
*Wide variation exists among practitioners with regard to diagnosis and treatment, with primary care physicians diagnosing and prescribing medications more readily than specialists. Read an example
*Adverse effects of medication are related to dosage.
*No clear neurological or physiological correlates of the disorder have been identified.  Brain scans and EEGs have been inconclusive.

Conclusions (for the time being):
There is probably a real disorder, mediated neurologically if not ultimately of neurological origin, characterized by a deficiency of attentional control, which afflicts a very few people.  This condition most likely arises in early childhood, responds to medication, and may be congenital.  At present, the medical and scientific communities have little idea as to causation.  This diagnosis, which properly belongs to this rare disorder, has become a fashion, and it is applied, along with the treatment of fashion, to a wide spectrum of behavioral clusters, many of which could not properly be called symptoms at all, but rather a set of behaviors at an extreme of the normal range of behavior for children, especially boys. (Read the DSM-IV criteria with this in mind!)  Alternately, behaviors labeled as ADHD are likely very often to be a child's response to an environment which is highly stressful, at school, home, or both.   It seems intuitive and very likely that drug companies, physicians, educational and other therapists, and parents with disturbed or difficult children saw in this vaguely defined disorder an opportunity to enhance their own self-interest.  The result is a huge cost to society in dollars and possibly permanently damaged children.

CLICK HERE FOR AN ENTIRELY DIFFERENT PERSPECTIVE.....

REFERENCES
American Academy of Pediatrics. (2000a). Practice guideline: Diagnosis and evaluation of a child with attention-deficit/hyperactivity disorder. Pediatrics, 105, 1158-70. Also available at http://www.aap.org/policy/ac0002.html

American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders, Fourth Edition (DSM-IV). Washington, D.C.: author.

Barkley, Russell A (1997). ADHD and the Nature of Self-control (1997). New York: The Guilford Press.