Oh sorry,one more thing. I don't know how it's dealt with now,because I can only speak to 15 years ago. But..
We showed up in MK Guest Services with a note from our son's doctor stating he had ADD. They gave us an index card with an orange stripe across the top. We were told that if we showed that card to a CM at a ride entrance,they would walk us around to the exit and we could get on the ride as others were getting off,so our son didn't have to wait on loooooong lines,testing his patience. Those were the days of waist packs,so I placed the card in mine,so all I would have to do is pull the card out enough to show the orange line and not call attention to ourselves and get people upset that we were " cutting the line". DH and I wanted to use it sparingly,as we also wanted DS to work on his coping skills. But not to the point of making all of us miserable. Disney is famous for its magical lines- just when you think you've reached the end,there's a whole new queue to deal with. Disney has caught on NOW,with interactive fun things along the lines,but back then,nothing but waiting. So I would send DH ahead to check out the true length of the line and then decide what to do. We ended up not using it that much,but it felt good having that back up with us. Just once did DS totally freak out. It was the Dinosaur ride. We didn't know about the ride except it had dinosaur robots. There was no line, so we walked right into a room that turned out to be a pre show. Once the room filled up,the room went dark and a deep voice started talking in a way that wasn't scary to us,but DS put the voice together with the dark room and started screaming. People immediately started yelling how horrible DH and I were subjecting our son to this just so we could go on a ride. They were hurling all sorts of insults while not parting so we could get out. They wouldn't move. A CM eventually stopped the pre show,fought his way through the crowd and lead us to an emergency exit. It was right to the pool for the rest of the day.........
I doubt they still use an index card,but it might be worth looking into,to see what accommodations they provide for ADD children. You may end up not using/ doing that accommodation,but it might take away some stress just knowing you have options if you need them.