Re: I think my son has add
In addition to a psychological evaluation, I would have him evaluated for learning disabilities as well. It is possible that he has a learning disability in reading that is causing some of the problem.
If you aren't ready yet to try medication, I would recommend that you take him to a psychologist rather than a psychiatrist for testing. A psychiatrist is much more likely to "push" for medication.
I think that you are right to have him evaluated even if you don't want to try medication. The information you get will be valuable. And, once you have a diagnosis, there are modifications that can be made in school to help him. It's definitely worth doing!