TNF and major depressive disorder: Previous studies comparing patients with depressionversus healthypeople found that lower blood levels of eicosapentaenoic acid anddocosahexaenoic acid increased the synthesis of n-6 fatty acids and n-6 eicosanoids and interleukin(IL)-6, tumor necrosis factor (TNF)-α, and C-reactive proteinconcentrations.6 Studies have reportedthat insufficient dietary intake of n-3 polyunsaturatedfatty acid (PUFA) is one cause of depression and is also associatedwith cardiovascular disease.7,8 The metabolism of serotoninhas a significant correlation with depression.