Don't get me wrong, I don't it's the explanation 100% for sure. I just think there is enough evidence to suggest that it may be a factor. None of this is 100% and even the experts don't understand how dopamine works 100%. Some experts even think it's a combination of factors. I just think it's a good suggestion that dopamine agonists have some effects. I've also heard of those being used inconjuction with anti-anxiety meds for a while because while anxiety doesn't cause stuttering, it does make it worse. Stuttering in general is difficult to study because it's so rare, so it's hard to get a good sample size. I've also read that certain medications that are used to treat anxiety don't work at all basically, while dopamine agaonists do have some effect in some people. You're right that some people don't respond at all, but that doesn't mean it isn't correct for some people. Usually very few things in studies are 100%, it's generally enough to prove that it does more benefits than harm. But then you also have to get into the fact that people respond differently to these kinds of medications also. It's a very complicated thing. I don't that they're wrong to study this further though. If it doesn't pan out, well it didn't. But I think enough suggesgive evidence is there to at least warrant further study.