There are a couple of posts on ketosis and brain function on Emma's blog that warrant a read, especially with Failsafe additions (read Emma, I don't know much about Failsafe). Ketogenic diets are in the news in the UK for epilepsy management at the moment. With the list of neurotransmitter effects that Emma details there is very clear cut logic to looking down this route for a fairly wide range of brain problems. As well as epilepsy and bipolar disorder I've heard anecdote on Dr Bernstein's forum for Tourette's. Obviously there is a certain amount of stuff about gluten/casein (A1 I presume) and schizophrenia.