When there is not enough stimulation for a very intelligent child they may get bored and tune out. The parents knew better and found an advanced science program for their son. He still does not have a high school diploma. I tell you, it's not easy to be smart in this world where many want you to be average. Of course, there's always the issue of diet too.
Some kids are particularly sensitive to refined sugar, additives, preservatives, etc.
In these children such products can cause a great variety of symptoms, including those normally attributable to ADD, as well as other problems, like headaches, allergies, skin eruptions, etc. There are specialists who work with detoxifying programs and they claim a lot of success. And then there is homeopathy. As a homeopath, I treat ADD as a part of the overall chronic condition. I take a complete case, paying equal attention to all issues in the child' s case, including any physical and psychological symptoms present.