Originally Posted by pharnabazos
An article in Pediatrics about a year ago suggested a direct correlation between childrens' exposure to TV between the ages of 1.5 and 3.5 and then subsequent ADHD at age 7.
They were Danish kids--and only 2% of Danish kids that age watch TV, versus 50% (!) of American kids.
[PEDIATRICS Vol. 113 No. 4 April 2004, pp. 708-713
Early Television Exposure and Subsequent Attentional Problems in Children]
Trouble with correlational studies is that they do not imply causation... which you are. Perhaps kids with AD/HD prefer TV more than other kids?
I'm a psychology professor and did my Ph.D. dissertation on adult AD/HD. To discuss the potential benfits of exercise to a sufferer of AD/HD, you have to remember there are 3 types: AD/HD Hyperative/Impulsive type, AD/HD Inattentive type, and AD/HD Combined type (symptoms of both hyperactivity and inattentiveness). The AD/HD - I type is the least common, and I can't really see how riding a bike would help that much. In both AD/HD-HI and AD/HD-Co the core symptom is believed to be impulsivity. This, in turn, affects a host of executive cognitive functions like memory, rule following, emotional control, and so forth.
A common myth in popular culture is that AD/HD people can't stay focused on things. They can, if it is stimulating enough. For example, many AD/HD people can play video games for hours on end. But see what happens when they have to do something tedious or rote, like writing an essay or listening to a boring lecture. A person with AD/HD might do very well at a bike messenger job (like Treespeed mentioned) because there is lots of variety and stimulation. Put them in a cubilcle doing accounts receivable and they will have a lot of trouble.
There are no known benefits to having AD/HD. People can cope with the disorder by finding activities that suit their need for stimulation and variety. People with AD/HD may enjoy a chaotic and risky environment more than others... but will be more accident prone. Medications help reduce levels of impulsivity and give other executive functions a better chance to kick in. Strenuous exercise provides an outlet for surplus physical energy, some novelty, and is just plain good for you. In other words, I can't think of any way that cycling would be better for AD/HD sufferers than it would for anyone else.
The prevalence rate for AD/HD is not believed to have changed over the years. More people are diagnosed with it now (and many are misdiagnosed with it). Unfortunately, there is a tendency to assume every misbehaved child has AD/HD, and that may not be the case. Correlations with environmental pollutants, birthing complications, and parenting practices exist, but have not proved decisive. Heredity seems to play a big role. By the way diet does not. Special diets like the Fiengold diet have not shown any efect in controlled studies.
Hope this helps answer some questions...