Risk factors for depressive disorders in very old age: a population-based cohort study with a 5-year follow-up

Depressive disorders are common among the very old, but insufficiently studied. The present study aims to identify risk factors for depressive disorders in very old age.

The present study is based on the GERDA project, a population-based cohort study of people aged ≥85 years (n = 567), with 5 years between baseline and follow-up. Factors associated with the development of depressive disorders according to DSM-IV criteria at follow-up were analysed by means of a multivariate logistic regression.

At baseline, depressive disorders were present in 32.3 % of the participants. At follow-up, 69 % of those with baseline depressive disorders had died. Of the 49 survivors, 38 still had depressive disorders. Of the participants without depressive disorders at baseline, 25.5 % had developed depressive disorders at follow-up. Baseline factors independently associated with new cases of depressive disorders after 5 years were hypertension, a history of stroke and 15-item Geriatric Depression Scale score at baseline.

The present study supports the earlier findings that depressive disorders among the very old are common, chronic and malignant. Mild depressive symptoms as indicated by GDS-15 score and history of stroke or hypertension seem to be important risk factors for incident depressive disorders in very old age.