Optimal brain function requires the ready availability of brain critical nutrients,
especially during periods of extreme stress. Deficiencies of brain-specific nutrients,
in addition to inadequate calories, may not only substantially contribute to suboptimal
cognition and alertness, but may manifest as severe psychiatric disorders including
adjustment disorders, major depression, impulsive violence and suicide. The
mammalian brain is primarily composed of fats and lipids, usually 60% wet weight.
Approximately 30% of fatty acid pool cannot be made de novo and must be obtained
through the diet and are thus termed essential fatty acids. Seafood, fish oils and fortified
foods are rich sources of the long-chain ω-3 fatty acids (ω-3 LCFAs: eicosapentaenoic
(EPA), docosapentaenoic (DPAω-3), and docosahexaenoic acids (DHA)).
DHA is selectively concentrated in neuronal membranes comprising 14% of total
fatty acids. Plausible biological mechanisms linking dietary deficiencies of ω-3 LCFAs
with psychiatric illness include: depletion of serotonin and dopamine levels by 50% in
animal models, impaired connectivity. This leads to an irreversible disruption in the neuronal
pathways that regulate behavior neuroinflammatory processes and dysregulation
of the hypothalamic pituitary adrenal axis. This is another demonstration of the therapeutic use of omega 3 fatty acids in different pathological conditions.

Hibbeln JR Depression, Suicide and Deficiencies of Omega-3 Essential Fatty Acids in Modern Diets World Rev Nutr Diet. Basel, Karger, 2009, vol 99, pp 17-30