Cognitive improvement following treatment in late-life depression: relationship to vascular risk and age of onset.

OBJECTIVES: To test the hypothesis that the degree of vascular burden and/or age of onset may influence the degree to which cognition can improve during the course of treatment in late-life depression.
DESIGN: Measurement of cognition both before and following 12 weeks of treatment with sertraline.
SETTING: University medical centers (Washington University and Duke University). PARTICIPANTS: One hundred sixty-six individuals with late-life depression. INTERVENTION: Sertraline treatment. MEASUREMENTS: The cognitive tasks were grouped into five domains (language, processing speed, working memory, episodic memory, and executive function). We measured vascular risk using the Framingham Stroke Risk Profile measure. We measured T2-based white matter hyperintensities using the Fazekas criteria.
RESULTS: Both episodic memory and executive function demonstrated significant improvement among adults with late-life depression during treatment with sertraline. Importantly, older age, higher vascular risk scores, and lower baseline Mini-Mental State Examination scores predicted less change in working memory. Furthermore, older age, later age of onset, and higher vascular risk scores predicted less change in executive function.
CONCLUSIONS: These results have important clinical implications in that they suggest that a regular assessment of vascular risk in older adults with depression is necessary as a component of treatment planning and in predicting prognosis, both for the course of the depression itself and for the cognitive impairments that often accompany depression in later life.