Sal, I think it's more saying that low dopamine can lead to Cushing's. I would assume that, once you HAVE Cushing's, you can't try to retroactively fix the cause. I don't know, though, because I can't read the link, only your comments. (link = broke)
I do find this really, REALLY interesting, though, since I've had ADHD since I was like 2, and they've found that people with ADHD have lower levels of dopamine.