I'm sorry, but I don't know much about this. I know that some of these herbals and vitamins for ADHD are basically the same but are just different brand labels.
Omega 3s are an important factor in keeping things under control and do help, as does a healthy diet.
If you can find a local homeopath that treats children, that would probably be your best bet to start.
An allergist can test your child for allergies, but from my experience, they missed the mark on food coloring. They said she didn't have an allergy to the dye they used, but she rages when she's had any food coloring. She doesn't have a typical allergy to it, with skin rashes.
I started Missy on Feingold and gradually introduced foods to her. In the beginning, certain foods were no-no because I noticed bad reactions from her, such as pineapple. Once she was on the diet for approximately 6 months, she got a bit better.