title: Hopelessness the "active ingredient"? Associations of hopelessness and depressive symptoms with interleukin-6.
abstract: OBJECTIVE
  Previous research has revealed a relationship of depressive symptoms and hopelessness with cardiovascular diseases (CVDs) which are associated with elevated levels of interleukin-6 (IL-6). The objective of this study was to explore whether depressive symptoms and hopelessness are independent predictors of IL-6 levels.
  
  
  METHODS
  Hopelessness, depressive symptoms, and IL-6 were measured in 45 Swedish adults (26 women and 19 men; age range: 31-65 years). Two separated linear regressions were conducted with hopelessness and depressive symptoms serving as individual predictors of IL-6. Another regression analysis examined whether the two predictors predict IL-6 when controlling for each other. The regression coefficients of the models with one predictor and with both predictors were compared.
  
  
  RESULTS
  As predicted, after adjusting for age, BMI, illness, smoking, and gender, more depressive symptoms and more hopelessness predicted higher IL-6 levels in independent regressions. When controlling for each other, hopelessness, but not depressive symptoms, predicted IL-6 levels. Finally, when controlling for hopelessness, the regression between depressive symptoms and IL-6 level was significantly reduced; however, there was no significant change in the regression between hopelessness and IL-6 level when controlling for depressive symptoms.
  
  
  CONCLUSIONS
  Thus, these results suggest that depressive symptoms and hopelessness are not independent predictors of IL-6 levels. Future research should explore the interplay of hopelessness and depressive symptoms on other risk factors of CVDs.
authors.affiliation: University of Louisville, Kentucky 40292, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Mitchell
authors.affiliation: Dept. of Educational and Counseling Psychology, University of Louisville, Kentucky 40292, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Pössel
authors.affiliation: Linköping University, Sweden.
authors.forename: Elaine
authors.initials: E
authors.lastname: Sjögren
authors.affiliation: Linköping University, Sweden.
authors.forename: Margareta
authors.initials: M
authors.lastname: Kristenson
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood / Q000523:psychology; D005260:Female; D065026:Hope / Q000502:physiology; D006801:Humans; D015850:Interleukin-6 / Q000097:blood* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012044:Regression Analysis; D013548:Sweden
chemical_list: D015850:Interleukin-6