Laura,
I just had to comment on this one. My dd had night terrors from age 2-5. When she got to 3rd grade, she had some meltdowns. We took her to a counseler, who said while she had "some" symptoms of OCD, she did not have enough symptoms to be diagnosed. She is a perfectionist. I believe this was related to being gifted. I think most of her problems were because she had a horrible teacher and was not being challenged. The counselor coached her in coping techniques, the school gave her more challenging work and the problem went away.
One thing to ask yourself, do the behavoirs he is experiencing, happen at school AND at home? Or other places too? There is numerous research (google it) about gifted kids being misdiagnosed.
Trust your instinct. You know your child best.
