The association between stroke, depression, and 5-year mortality among very old people

Depression after stroke has been associated with increased mortality, but little is known about this association among very old people.

A population-based study among people ≥85 years of age was conducted in northern Sweden and Finland, comprising cross-sectional assessments and subsequent survival data. The 452 individuals who had completed the Geriatric Depression Scale-15 assessment were selected. Depression was defined as a score of ≥5 on the geriatric depression scale.

Of those with a history of stroke, 38 of 88 (43.2%) people were depressed, and 11 of the 38 (28.9%) were treated with antidepressants, compared with 91 of 364 (25.0%) depressed (P=0.001) and 17 of 91 (18.7%) treated with antidepressants among those without stroke. Having a history of stroke and ongoing depression was associated with increased 5-year mortality compared with having only stroke (hazard ratio, 1.90; confidence interval, 1.15-3.13), having only depression (hazard ratio, 1.59; confidence interval, 1.03-2.45), and compared with having neither stroke nor depression (hazard ratio, 2.50; confidence interval, 1.69-3.69). Having only stroke without depression did not increase mortality compared with having neither stroke nor depression.

A history of stroke was associated with increased mortality among very old people but only among those who were also depressed. Depression seemed to be underdiagnosed and undertreated.