One thing you can do is work on basic social skills. Sometimes 'talkers' aren't good conversationalists. You can talk to HIM about this and work on back and forth conversation. There is also a system that our school uses that seems to really be helpful with kids. They call it the voice volume number system------ but basically, they go over 5 levels of talking. 5--- is emergency voice "fire", 4 is outside recess voice, 3 is regular talking voice 2 is whisper and 1 is silence. You can talk about during a lesson that the teacher is giving, that everyone has to be a 1 so everyone can hear. And when you are sitting at your desk working and want to talk to a neighbor, it is a level 2 whisper. When you are outside, go for your level 4 loud recess voice. Everyone has to know that at times, level 1 is appropriate. Like in church and whatnot. This helped my boy know when to apply his impulse control and when he didn't have too. good luck
I agree with the others I also have known many talkative children usually they were smart, very inquistive with many questions, I like that . I dont think it means they have a disorder,that will lead to serious drugs with side effects . .
Gotta agree with RockRose - at least with the info you have posted. To be diagnosed with ADHD you have to show the symptoms in at least two different places. If the school agreed in the first tests, then he would have been diagnosed. However, intelligence can mask some of the symptoms. And intelligence can also cause the same problems you are talking about.
I have had very talkative kids in class (5th grade), and I simply insisted they follow the class rules. You don't interrupt. It takes time and consistency, but they learn. The teacher and you need to follow that rule. If you practice at home - he cannot interrupt - it will carry over to school. But it will not happen overnight.
There are also several neat books in the "Learning to get along series". They are pitched a bit below his level (aimed at 4 to 7), but it might be worth getting one and giving it a try. I would suggest "Share and take turns" found here - http://www.amazon.com/Share-Take-Turns-Learning-Along/dp/1575421240/ref=pd_sim_b_6
If you/he like it - you will find several more listed on the link I gave you. If nothing else they provide a way to talk about whats going on.
If there are other things that bother you - I monitor the ADHD forum and would be glad to answer any specific questions. But at least for right now - I think Rockrose's conclusion is right on.
When you say you had him checked for ADHD and it was "negative", it's not like a blood test.
It's a decision made by the doctor, based on input from the teachers and his/her experience with your child.
My guess is he will turn out great and your son's teacher wants silence in the classroom, which he is not providing. There are WAY worse things in life than talkative children.