The association between stroke, depression, and five-year mortality among very old peopleIn this population-based study, Drs Hornsten et al examine the effect of depression on mortality among stroke survivors of very old age. Depression is being increasingly recognized as a common long-term effect in stroke survivors.
In this study, depression seems to be associated with increased five-year mortality in very old (defined as ≥85 years of age) patients. Stroke patients without depression or depressed patients without stroke were found to have increased chances of survival compared to stroke patients with ongoing depression. Is it notable that although the effect appears robust in univariate analysis, adjusting for cognitive decline and functional dependence significantly weakened the association, underlining the complex interplay between those factors.
The results are interesting, but the limitations of the study do not allow for robust conclusions: The sample of stroke survivors with ongoing depression was relatively small. Additionally, depression was not diagnosed by medical record review or antidepressant use but rather by using the Geriatric Depression Scale, therefore essentially excluding a number of successfully treated patients and not allowing answer to the question whether depression per se or untreated depression only are associated with increased mortality. Further investigation of the effect of depression and its treatment in this unique but increasing subpopulation of survivors is necessary.