How about you try food supplements that have shown to have equal efficacy to Ritalin,Multiple vitimin with B Complex
and Vit C . also Fish oil
and been tried by many parents,with success, go into your local whole food store,if you have one called "Sprouts "they are very good and will go online for you to find what you need in a Natural Remedy to help you.If the drugs you have been trying dont work its time to find something less invasive that will, Good Luck.