Maybe an evaluation from another pdoc. may help?
So often, kids get mis-diagnosed as being ADHD when actually they may be Bipolar, similar symptoms that overlap,being mistaken for ADHD. Which is sad, if a child or even an adult have been DXed with ADHD, and then prescribed meds for it, can really screw up things for a Bipolar. Bipolars can also be ADD, so in such cases, meds for both can be used, mood stabilizer and other meds the doctor feels will help minimize or remove symptoms.
Maybe you son has dual disorders, it's possible and not rare. Beauty part, is with a proper DX, by reputable psychiatrist, makes all the difference, helping the patient and family to a better life. Just, my 2 cents. I strongly feel, only psychiatrists should make the final DX, GP's, etc. are not qualifed, though they have the training in med school, it isn't the same, it's less intense, that is why we have specialists in all areas of medicine. A GP, or PA may have an idea of a DX from seeing the symptoms in a patient, suffering some sort of mental disorder(s) due to so many disorders having similar symptoms, but it is a specialist that would be best to follow through with, and any good GP will refer their patients to someone.
I hope things work out for you, I know how frustrating this can be for you and your child. My heart goes out to you both.
Take care,
DE


BTW
I have 2 DXes, ADD and Bipolar-II, take meds for both and have come a long way, in a positive sense.