I went to a naturopath a few months ago and he made me do a seft test that is found in chapter 3 of the book "the edge effect". The test is suppose to identify what brain chemicals are dominant for you so you can supplement the chemicals you a deficient with. I was identified as being GABA deficient, but I haven't got around to taking any supplements as I was fairly ballanced and don't have any real bothersome symptoms. When I start working again soon I might try taking GABA if I continue to have trouble focusing.
My mother was also identified as being GABA deficient and she has been taking supplements for awhile now. She swears by it.
"I know that victory is sweet, even deep in the cheap seats."