Cognitive performance in depressed older persons: the impact of vascular burden and remission. A two-year follow-up study

OBJECTIVES: Depression is associated with an increased risk of cognitive decline. The present study compared two-year change in cognitive performance between depressed older persons and a non-depressed control group, between remitted and non-remitted patients, and evaluated whether vascular burden at baseline was associated with more cognitive decline in depressed older persons.

METHODS: Depressed patients (n = 378) aged ≥60 were recruited from mental healthcare institutes and general practices, and a non-depressed control group (n = 132) was recruited from general practices. A DSM-IV depressive episode was established with the Composite International Diagnostic Interview, and processing speed, working memory, verbal memory and interference control were evaluated with three neurocognitive tasks at baseline and 2 years later. A modified Framingham Risk Score, ankle-brachial index, and history of a vascular event defined vascular burden at baseline.

RESULTS: After adjusting for baseline cognitive performance, age, sex, and education level, depressed older persons had worse processing speed and verbal memory scores at follow-up than controls (regression coefficients: -0.172; p = 0.042 and -0.309; p = 0.001, respectively) but did not differ in the other two-cognitive outcomes. In the sample of depressed patients, remission status at 2 years follow-up and baseline vascular burden did not predict cognitive performance at follow-up, after adjustment for baseline cognitive performance, age, sex and education level.

CONCLUSIONS: Our findings suggest that cognitive deficits in depressed older persons are not just a manifestation of depression. In addition, vascular burden was not associated with worse cognitive decline in a sample of depressed older persons. Copyright © 2016 John Wiley & Sons, Ltd.