I think (may be a controvesial thought) that alot of the kids classified as ADHD, are ADHD like, but not gentically born ADHD, the environment they are in makes them act as such. (parental techniques, starting a kid at school too soon, too much Tv at 1 year old etc., ) While there are many ADHD that no changes in parenting will change. Just an opinion. (whereas ASD is not a parent issue, in any cases, it has a physical/nuerological basis) Nurture Vs. nature.
I would tend to agree with this, in some cases anyway.
I've seen concern expressed in the media about the number of children dxed as ADHD and medicated when it may simply be the case that adults are failing to realise that children do have loads of energy and if they are denied the opportunity to run that energy off or express themselves as children should then their activities will become more destructive. They say that children are given much less freedom these days just to be children and to enjoy unsupervised, or minimally supervised outdoor play. Instead they are kept indoors and expected to act more like mini-adults than as children. Medication is used to keep them placid and more controllable. Better to let them run about in the park for an afternoon and burn off all that energy!
Btw, I'm not saying this applies to all children dxed as ADHD, but quite possibly to some.