Prognosis of late life depression: a three-year cohort study of outcome and potential predictors

Abstract

Background: Late-onset depression (LOD) has a poor prognosis which may be worsened by the presence of cerebrovascular disease. Few studies have explored prospectively the influence of vascular risk factors on longer term prognosis.

Methods: The original study involved 50 patients with LOD and 35 healthy age matched controls. Follow-up was at three years. Baseline measures included clinical, neuroradiological and neuropsychological variables. Outcome was assessed by mortality, progression to dementia and clinical course of depressive disorder.

Results: Sixty-two (73%) of the original cohort agreed to be re-interviewed. Seven participants had died (all from the depressed group) and six developed dementia, all but one from the depressed group. Vascular dementia predominated (although not significantly so) among those with dementia at follow-up. For 28 depressed patients with complete follow-up data (56% of the original sample), poor outcome was predicted by lower High Density Lipoprotein (HDL), raised Erythrocyte Sedimentation Rate (ESR) and a higher score on the Hachinski Index scale and one test of immediate memory. Initial response to treatment was not associated with later outcome.

Conclusion: Late-onset depressive disorder is associated with a high rate of mortality and possibly dementia. Biochemical and inflammatory markers may be important in prognosis and their role should be confirmed in future studies.