Comorbidity of Cognitive Impairment and Late-Life Depression Increase Mortality: Results From a Cohort of Community-Dwelling Elderly Individuals in Rural Greece

J Geriatr Psychiatry Neurol. 2016 Jul;29(4):195-204. doi: 10.1177/0891988716632913. Epub 2016 Feb 25.

Abstract

Objective: To investigate the association of cognitive impairment (COGI) and depression with all-cause mortality and cardiovascular-specific mortality among community-dwelling elderly individuals in rural Greece.

Methods: Cognition and depressive symptomatology of 676 Velestino town residents aged ≥60 years were assessed using Mini-Mental State Examination (MMSE) and Geriatric Depression Scale (GDS), respectively. Eight-year all-cause mortality and cardiovascular mortality were explored by multivariate Cox regression models controlling for major confounders.

Results: Two hundred and one patients died during follow-up. Cognitive impairment (MMSE ≤ 23) was independently associated with all-cause mortality (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.13-2.18) and cardiovascular mortality (HR: 1.57, 95%CI: 1.03-2.41). Moderate to severe depression (GDS > 10) was significantly associated only with a 51% increase in all-cause mortality. A male-specific association was noted for moderate to severe depression, whereas the effect of COGI was limited to females. Noteworthy, COGI and depression comorbidity, rather than their sole presence, increased all-cause mortality and cardiovascular mortality by 66% and 72%, respectively. The mortality effect of COGI was augmented among patients with depression and of depression among patients with COGI.

Conclusion: COGI and depression, 2 entities often coexisting among elderly individuals, appear to increase all-cause mortality and cardiovascular mortality. Gender-specific modes may prevail but their comorbidity should be carefully assessed, as it seems to represent an independent index of increased frailty, which eventually shortens life expectancy.

Keywords: cognitive impairment; dementia; depression; elderly; mortality; survival.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cognition
  • Cognitive Dysfunction / epidemiology*
  • Cognitive Dysfunction / psychology
  • Comorbidity
  • Depression / epidemiology*
  • Depression / psychology
  • Depressive Disorder, Major / epidemiology*
  • Depressive Disorder, Major / psychology
  • Female
  • Geriatric Assessment / methods*
  • Greece
  • Humans
  • Male
  • Mental Status Schedule
  • Middle Aged
  • Mortality* / trends
  • Neuropsychological Tests
  • Proportional Hazards Models
  • Rural Population