CarolCB, I am praying for you
Have you tried the National Association for Child Development? They are in Utah. My sister was born with dyspraxia, which is much more severe that anything your grandson has. The public school system told her she would never speak when she was about 6 years old and gave her a computer to talk for her. My mother took her to the NACD in Utah, and they changed her life. Today she can talk like everybody else. The NACD treats many developmental disorders in children, and autism and dyslexia are included on their website. They could probably do something about ADHD too.
CarolCB, I am praying for you