when they are diagnosed?

I'm thinking from a psychological perspective. For example, do they feel different to other kids?

Like anything else, it probably depends on many factors. If the childs parents and siblings adhere to the same diet guidelines as the diabetic child, she/he will adjust easier.

Just as having a child with a handicap can be easier or difficult, depending on how you approach it, and communication is the key.

I had heart disease when I was a child, and nobody ever bothered to explain why I wasn't allowed to exercise or get upset. Again, communication is the key, or else the diabetic child will just sneak chocolate.

I whole heartedly agree..
The disease does not just affect the child it affects the whole family. the family unit must be proactive and helpful.
Thats why so many Self managment classes encourage brining the whole family of undrstanding age to learn.
Thats also why the camps are so great for kids.....
They providee understanding, compassion, education and allows everytone to see its no big deal.. its just apart of them and their child.....

given the proliferation of a variety of childhood diseases and allergies, such as peanut allergies and asthma, you'd think there wouldn't be a lot of shock where other children are involved.

it's amazing how resiliant some kids are.

I think if the child is aware early on and is used to the limitations that are set for them, then I think they would probably think that everybody is like them and I don't think they would dwell on it so much.