You could try fish oil and see what happens. It's pretty inert stuff and it truly is a magic pill for attention issues, hyperactivity, the works. You might have to play with the dosage, though.
I take flaxseed oil, and it helps TREMENDOUSLY... I can't bring myself to take fish oil, even the kind they say isn't "fishy". It's probably why I have issues with ADD... not enough fish in my diet.
My dad hates fish, so he freezes the fish oil capsules. He said it ensures no fish taste (or even fish belches, which I have experienced before when taking fish oil capsules, and it's not nice!).
You might give the freezing a try. The fish oil really is supposed to be better than the flax from what I've read.
