Tumor necrosis factor-alpha and mood disorders in the elderly

There is a large body of evidence that depression is one of the major clini cal problems in the elderly. As matter of fact, several studies have addres sed their attention on mood disorders in aged subjects, suggesting differen t etio-pathogenetic factors. Recently growing interest has been concentrate d on the role of immunological alterations related to de-pression showing c ontradictory data. The aim of this study was to evaluate the correlation be tween depression and alterations of the cytokine network in aged patients. We included 45 elderly subjects (mean age 80.1 + 12.4 years). All subjects underwent a wide bio-chemical assessment, as well as psychological (mini me ntal state examination: MMSE; geriatric depression scale: GDS) and self-suf ficiency (activity of daily living: ADL; instru-mental activity daily livin g: IADL) examinations. Student's t-test and linear regression analysis were carried out for statistical evaluation. According to international criteri a, we defined depressed all subjects with GDS score > 11. (n = 22). They sh owed higher values of tumor necrosis factor-alpha (TNF-alpha) (47.4 +/- 11. 6 vs 8.7 +/- 4.0 pg/ml; p < 0.0001), and lower values of serum iron concent rations (48.3 +/- 12.2 vs 92.5 +/- 16.6 mg/dl; p < 0.0001), than the contro ls. No significant differences were found in the MMSE scores and serum chol esterol levels of the two groups. Moreover, the depressed subjects were fur ther divided in 2 subgroups, on the basis of their nutritional status: 14 s ubjects were affected by protein-energy malnutrition (PEM), and 8 of them w ere well nourished subjects. PEM subjects had higher TNF-alpha, C-reactive protein (CRP) and GDS score, and lower serum iron levels than the well nour ished group (p < 0.001). Therefore, our data suggest that depression is clo sely related to alterations of the cytokine network, particularly in subjec ts affected by homeostatic balance failure syndrome. Nevertheless, further studies are necessary to establish both the strength and the etio-pathogene tic meaning of this correlation.