A review.Fatty acids (FAs) in the brain have mech. and even metabolic functions as well as actions related to transmission underlining their importance in the very basic effects of brain function: generation and conduction of elec. potentials.Two of the most abundant marine FAs, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), may play important roles in the preservation of mental health.EPA has important psychotropic actions, which could be used for treatment of depression and even schizophrenia in combination with drugs.DHA may be used for preservation of brain cell membranes perhaps useful for prevention or even treatment of dementia.