[The role of folates in the diverse biochemical processes that control mental function].
A variety of studies indicate that folate deficiency is associated with the appearance of problems of a neuromuscular or neurological nature such as depression, muscular and mental fatigue, states of confusion and non-senile dementia, and that these processes improve fully or partly when the deficiency is corrected. Because of the role of folates in the reactions in synthesis of neuro-transmitter and elements of neuron structure, it is not surprising that a deficiency is associated with depression and other mental problems. Folates are involved in the synthesis of S-adenosylmethionine (SAM) which is the main contributor of methyl groups in the nervous system and whose action as an antidepressive agent is confirmed. They are also involved in the synthesis of glutamate which is an excitant neurotransmitter, and in the formation of puric and pyrimidic bases. An alternative mechanism for explaining the etiopathogenesis of folate deficiency in depression and other mental disorders involves the regeneration of tetrahydrobiopterin (THB) which is an essential cofactor in hydroxylation process in the brains of mammals. Folate deficiency is a common nutritional problem in many groups of the Spanish population and, given the role of this vitamin in the operation of the nervous system, we might consider the possibility that, in some case, folate deficiency may cause or aggravate some alterations to mental function.