Sara, that's a good point. I can only speak for my boys who are not typical ADHD but have the Pervasive Developmental Disorder (PDD) thing going as well, but both have extreme anxiety issues.
We have medicated both with stims and this has generally been successful. When not medicated, their anxiety is no better, because I think their not being able to cope (everything is confusing, they have much more trouble staying focussed) also pushes their anxiety up, so it balances out. The medications make it easier for them to rationalise their anxiety, at least partly.
Also, we are just now dealing with an incident that in the past would have had difficult child 3 screaming in outbursts as a result of anxiety - and he's not. What happened? When we went to drama class on Wednesday night, difficult child 3 insisted (as usual) on bringing his backpack with him, the one that has every Nintendo DS game he owns. He also had his DS and a couple of games in his carry case. Now, for difficult child 3, his DS is almost surgically attached to him.
And he left his backpack behind. Hundreds of dollars worth of games in there.
Was he anxious? I expected tears, screams, rages, the lot. Nothing. Instead, it was, "They're all my friends. Someone will have picked it up and will bring it along next week."
He is very trusting. He did nag me to telephone to let them know at the hall that he'd left his bag, and they hadn't seen it. We got a phone call today - the drama teacher took it home with her, it is safe. I told him - he is calm.
And he is on high doses of stims.
Every case is different, it is important to be aware of the potential for problems with stims and anxiety, but it can work out much better even so, as it did for us.
And also a lesson from us - as MWM said, a combination of ADHD and anxiety, as well as some of the other things - further evaluation wouldn't hurt, to make sure you're not dealing with something like Pervasive Developmental Disorder (PDD). The sooner you know, the sooner you can get that extra bit of more directed support you need. It took us another nine years to get difficult child 1 properly diagnosed.
Marg