Association of interleukin-6 and other biologic variables with depression in older people living in the community

J Am Geriatr Soc. 1999 Jan;47(1):6-11. doi: 10.1111/j.1532-5415.1999.tb01894.x.


Objectives: The prevalence of depression increases with age, as does the prevalence of higher levels of the cytokine interleukin-6 (IL-6). This analysis was performed to determine the association between increased levels of this cytokine and depression in a population-based sample.

Design: Cross-sectional cohort study.

Setting: Rural and urban counties in North Carolina.

Participants: Community-dwelling older people.

Measurements: The association between IL-6 and other biologic variables with self-report depression was examined in 1686 persons aged 70 years and older in the third in-person survey wave (1991) of the Duke Established Population for Epidemiologic Studies of the Elderly (EPESE). Bivariate associations were established by the Spearman correlation, adjusted for age. A stepwise linear logistic regression model was used to derive a final model to assess multivariable effects on CES-D scores.

Results: Depression was correlated with IL-6 (P = .011), D-Dimer (P = .017), alpha-1-globulin (P = .023), alpha-2-globulin (P = .002), and beta globulin (P = .012). After controlling for age, race, and gender, IL-6 levels remained the only biologic variable significantly associated with depression (P = .035).

Conclusion: These data suggest that the inflammatory marker, IL-6, is associated with depression in older people in this cross-sectional study. These results are compatible with the hypothesis of cytokine (IL-6) stimulation in geriatric depression as part of an overall immunoendocrine dysregulation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Age Distribution
  • Aged / psychology
  • Aged / statistics & numerical data*
  • Alpha-Globulins / metabolism
  • Analysis of Variance
  • Beta-Globulins / metabolism
  • Biomarkers / blood
  • Cross-Sectional Studies
  • Depression / blood
  • Depression / epidemiology*
  • Depression / immunology*
  • Female
  • Fibrin Fibrinogen Degradation Products / metabolism
  • Follow-Up Studies
  • Health Surveys
  • Humans
  • Interleukin-6 / blood*
  • Linear Models
  • Male
  • North Carolina / epidemiology
  • Prevalence
  • Statistics, Nonparametric


  • Alpha-Globulins
  • Beta-Globulins
  • Biomarkers
  • Fibrin Fibrinogen Degradation Products
  • Interleukin-6
  • fibrin fragment D