title: Low-grade inflammation predicts persistence of depressive symptoms.
abstract: BACKGROUND
  Evidence suggests that depression is cross-sectionally and longitudinally associated with activation of inflammatory response system. A few studies, however, have investigated the longitudinal relationship between raised inflammatory biomarkers and persistence of depressive symptoms. We examined the temporal relationship between serum levels of inflammatory biomarkers and persistence of depressive symptoms among older participants.
  
  
  METHODS
  Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depressive symptoms at baseline and at 5-year follow-up in 656 participants (233 men, 423 women) aged >60 years of the Rotterdam Study. Markers of inflammation interleukin (IL)-6, alpha-1-antichymotrypsin (ACT) and C-reactive protein (CRP) were assessed at baseline, and all participants taking antidepressant medications were excluded from the analysis.
  
  
  RESULTS
  No cross-sectional association was found between IL-6, ACT and CRP with depressive symptoms at baseline. However, higher levels of IL-6 and CRP predicted depressive symptoms at 5-year follow-up. Adjustment for confounding variables had no impact on the observed associations. Similarly, a positive association was found between baseline levels of IL-6 (OR = 2.44, p = 0.030) and CRP (OR = 1.81, p = 0.052) and persistence of depressive symptoms over 5 years.
  
  
  CONCLUSIONS
  Our data suggest that dysregulation of the inflammatory response system is associated with a more severe form of depression more likely to re-occur.
authors: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, WC1E 6BT, UK. a.zalli@ucl.ac.uk.
authors: A
authors: A
authors: Zalli
authors: Department of Epidemiology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors: O
authors: O
authors: Jovanova
authors: Department of Psychiatry, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors: W J G
authors: WJ
authors: Hoogendijk
authors: Department of Epidemiology, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors: H
authors: H
authors: Tiemeier
authors: Department of Epidemiology and Public Health, University College London, 1-19 Torrington Place, London, WC1E 6BT, UK.
authors: L A
authors: LA
authors: Carvalho
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000032:analysis / Q000378:metabolism; D003863:Depression / Q000378:metabolism / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000523:psychology*; D015850:Interleukin-6 / Q000378:metabolism; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D000514:alpha 1-Antichymotrypsin / Q000378:metabolism
chemical_list: D015415:Biomarkers; D016207:Cytokines; C508600:IL6 protein, human; D015850:Interleukin-6; D000514:alpha 1-Antichymotrypsin; D002097:C-Reactive Protein
keywords: Aging; Chronic illness; Epidemiological; Mood disorder; Pro-inflammatory cytokines; Psychosomatic