Fidgeting, as it turns out, helps kids with Attention-Deficit Hyperactivity Disorder focus. So just like grown-ups need a cup of coffee before tackling a problem, kids with ADHD may tap their feet, swivel in their chairs or bounce in their seats while their brains are busily figuring out that math test.
...
What makes ADHD kids different? Rapport suspects they are "under-aroused" -- that their brains do not produce enough dopamine to keep them alert during normal day-to-day activities -- so the kids move around to jiggle or wake their brains and bodies up.
For many teachers, like Darcey Eckers of Orlando, Rapport's findings confirmed what she has seen in years of teaching.

"These kids have to move," Eckers said. "It can be any kind of movement -- some part of their body, it doesn't even matter what part."

(article)

Thanks to a tip from Michelle, I recently read a bit of the book Driven by Distraction. I identifed very strongly with some of its case studies, and then took an online ADD test, resulting in the realization that I have (mild) Hyperactive ADD. Unlike the attitude I saw in DBD, I don't feel that this absolves me of any responsibility for my actions, successes, or failures. Still, it is interesting to know that there are lots of other people out there who suffer from some of the same difficulties I do: an inability to stay focused on one thing, starting many projects and not finishing them, getting bored easily, having their mind race when they try to relax, difficulty sitting still, lots of trouble with organization, difficulty doing mundane tasks like paying bills and doing taxes, etc. Being practical, the main thing I want to know is what to do about it. I am into using chemicals (drugs, nutrients) to alter behavior, so I looked there for a potential "quick fix" (although they rarely exist).

I happen to know a fair amount about neurochemistry and drugs for altering neurochemistry (just something I'm interested in), and I found it quite strange that Ritalin, an old drug with substantial physical side effects, is the standard treatment. While the stimulants seem to be quite effective at treating ADHD, I am concerned that short-term effectiveness is an easily seen benefit, while long-term problems are a harder to see cost, resulting in incorrect calculations as to their utility. The legal stimulants, like their illegal cousins cocaine and methamphetamine, may well cause long-term effects on the body and brain, and their long-term efficacy has been called into doubt. Here is a page of references I found on the subject.

One of the neat things which has happened in the past few decades is that we've discovered all sorts of drugs which affect the brain without affecting the body. I understand that lots of people feel that taking drugs is bad, and that taking drugs for ADD is bad, and I have no disagreement with that (here is a quick summary of the scientific evidence on alternative treatments). What I am curious about is, for those people who do choose drug therapy, if there are better drugs that they can use (more effective or fewer side effects).

Some of the theories on ADHD have to do with neurochemical imbalances, as explained in this useful site, for example. The effects appear to be complicated. As the above page says: "No single neurotransmitter deficiency appears to explain fully the array of medications which improve symptomatology in AD/HD. The single neurotransmitter concept is refuted by the inability of specific medications known to modulate individual neurotransmitters to improve symptoms. It is possible that AD/HD is due to imbalance of multiple inter-related neurotransmitters." Also "This would suggest that both norepinephrine and dopamine are involved in the etiology of AD/HD but attention was primarily mediated via dopamine pathways" , and "This would support the hypothesis that specific behavioral components of AD/HD are mediated by different neurotransmitter pathways." The genes that have been found so far that seem to be linked with ADD are related to the dopamine system. "While most neuroscientists and neuroscience wannabes are hesitant to reduce anything to a simple equation or catch phrase we might be on fairly firm ground in saying that attention problems may be seen as a dopamine deficiency." (from here).

Two of the most important drive/motivational related neurotransmitters are dopamine and noradrenaline (norepinephrine). It is thought that ADDers may be deficient in dopamine. The stimulants used to treat ADD all increase the release and inhibit the reuptake of dopamine. However, this is not the sole explanation, as L-dopa (the precursor to dopamine, which increases dopamine levels) does not help treat ADD, and some dopamine antagonists show modest benefits. Increasing noradrenaline is, unsurprisingly, also another way to treat ADD. Clonidine boosts some specific noradrenergic activity, as do some other drugs (such as the stimulants). "a change in noradrenergic function appears to be a necessary but not sufficient condition for improvement of AD/HD symptoms." (from here)

The current drugs used are:

Methylphenidate (Ritalin):
http://hsc.virginia.edu/medicine/clinical/pediatrics/devbeh/adhdlin/methyl.html
http://www.rxlist.com/cgi/generic/methphen.htm

Dextroamphetamine (Dexedrine):
http://hsc.virginia.edu/medicine/clinical/pediatrics/devbeh/adhdlin/dextroamp.html
http://www.rxlist.com/cgi/generic/dextroamphetamine.htm

Clonidine (Catapress):
http://hsc.virginia.edu/medicine/clinical/pediatrics/devbeh/adhdlin/clonid.html
http://www.rxlist.com/cgi/generic/clonidin.htm

Since ADHD seems related to dopamine and noradrenaline, rather than the "dirty" stimulants, I would consider drugs such as NARI's, eugeroics (alpha-2-adrenergics), and dopamine boosters. Using PubMed, I set out to see whether research had been done on these compounds. It turns out that the medical establishment has done a fair bit experimentation with non-stimulant pharmacological treatment of ADHD. Summaries can be found here and here. Following are some of the specific drugs that seemed promising to me, given my general knowledge of neurochemistry, along with the research that has been done so far.

• Dopamine boosters:
  • Bupropion (Wellbutrin):
    While bupropion's method of action is not fully understood, it is not a MAOI, but seems to inhibit the reuptake of dopamine. It is marketed as an antidepressant and an aid to stop smoking. There has been some clinical research, and it seems to work pretty well (ref1, ref2). However wellbutrin does have some side effects, and it has not been accepted by the mainstream.
  • Selegiline (deprenyl)
    Selegiline is an irreversible selective MAO-B inhibitor, which is used to treat Parkinson's and for life-extension purposes. It prevents dopamine from being broken down by monoamine oxidase-B. In an animal model, it was found to prevent the impulsiveness component of ADHD. It has shown effectiveness in human treatment in some trials (also here), but other trials showed no effectiveness. For some reason it seems to be most often tested on those with ADHD & Tourette's syndrome.
• Noradrenaline boosters:
  • Reboxetine / Tomoxetine (Reboxetine description and research)
    Reboxetine has been FDA-declined in the USA (despite being approved in many other countries and used for years), but a very similar compound called tomoxetine is being tested on ADHD in the states and is showing great promise. The conspiracy theory is that the FDA did not approve reboxetine so that Eli Lilly (makers of Prozac), who have the patent on tomoxetine, can have the FDA-approved NARI. Whether or not this is true, tomoxetine has had excellent results in the recent studies (ref1, ref2) on using it to treat ADHD. It will probably be FDA-approved for treatment of ADHD, but until then, people who wish to use a NARI can get reboxetine from a non-US online pharmacy.
• Eugeroics:
  • Modafinil / adrafinil
    These are selective/specific noradrenaline antagonists. Modafinil is FDA-approved in the US for treatment of narcolepsy, and is notable for its lack of adverse effects on sleep, unlike amphetamines. In two studies, one on kids and one on adults, it was found effective for ADHD.

The good news is that in support of my intuition, positive results have been found for most of these drugs. The bad news is that none of them are well established as methods for ADHD treatment. Other than tomoxetine, all of them have been around for years. I can only speculate as to the reasons for this, inertia and conservativeness seem like the most likely explanations. I suspect it is much easier for the makers of ritalin to maintain/increase their market share than for the makers of other drugs to break in. Many doctors are conservative about trying new drugs, and prefer to stick to things which they cannot be questioned for prescribing. In general, mainstream treatments seem to change pretty slowly. Still, with the current backlash against ritalin (due to it being overprescribed as well as unsafe), perhaps the window is open. And regardless of what the establishment does, if you or a loved one has ADHD and are the sort of person who likes to research the drugs he takes and pick the best ones, rather than just asking a doctor, you should find this information useful.