Hi, can someone lead me to information about paleo diet and depression, or specifically bipolar disorder. I'd like to learn more about how insulin resistance/hyperinsulinemia has a negative impact on neurotransmitters, and that simply supplying more carbs for more serotonin is not the answer. 

I don't need to get too deeply into the complexities of serotonin metabolism, but a summary would be nice!

On a slight tangent, a friend recently told me that  EPA and DHA have very different effects, and that specific disorders are sometimes best treated with one or the other rather than both together.  According to Dr. David Horrobin's lecture at the fall '99 ACAM conference, EPA is used for function, and DHA for structure.  (This is not a hard and fast rule, but a helpful generalization.)  People with functional mental disorders (schizophrenia, major depression, and bipolar depression) benefit most from a formula high in EPA and low in DHA; children with cystic fibrosis, a structural membrane defect, benefit from DHA but not from EPA or EPA/DHA mixtures.  Apparently in both these contexts, EPA and DHA compete with each other and blunt the therapeutic effect if given together.

People with the mental disorders Horrobin talks about share a common gene; which disorder a person has depends on other additional genes.  The gene in question causes overactivity of the enzyme phospholipase A-2.  This enzyme uncouples long-chain fatty acids (both arachidonic acid and EPA) from phospholipids.  Nerve cell membranes don't work well without these fatty acids, hence, the disorders.  EPA (but not DHA) not only replaces some of the lost fatty acids, but also inhibits the overactive enzyme and in many cases restores near-normal function.

Any comments appreciated.

Thanks in advance,
Karen