I experience racing thoughts too. When you say "brain chatter" what do you mean by that. Do you feel as if there is conversation occuring? Do you ever feel llike something/someone is speaking to you (though it is in your mind and not audible--it comes through as a thought. Just wondering because I experience it everyday and sometimes is gets to be too much to handle.
have you been diagnosed with anything else besides ADHD? Take any other meds? I have been diagnosed with Bipolar and take Abilify, also take Ritalin for ADHD. I thought maybe the Ritalin was the culprit, but it happens even when I don't take it. I am starting to look into other explanations for this torture, as no medication has been able to take it away. I have found some very interesting info about people suffering the same thing that got relief through unconventional means--
Hope to hear back from you.
Take care!