Objective: Depression relates to vascular disease and is a candidate risk factor for dementia. We assessed the risk associated with depressive symptoms for Alzheimer-type dementia and vascular dementia.
Methods: Depressive symptoms (SCL-90 depression subscale) were assessed in 771 community-dwelling individuals age 55 years and older. Onset of dementia (N = 37) was recorded at serial assessments 3, 6, and 9 years after baseline.
Results: Depressive symptom scores predicted all-type dementia (OR = 1.06, 95% CI = 1.01-1.10), and vascular dementia (OR = 1.11; 95% CI = 1.03-1.19), but not Alzheimer-type dementia (OR = 1.04; 95% CI = 0.98-1.09). People scoring in the upper quartile of the SCL-90 depression scale (N = 180) were at increased risk for dementia (OR = 2.06, 95% CI = 1.01-4.22). Results were unchanged after co-varying for baseline mini-mental state exam and presence of vascular disease.
Conclusion: Depressive symptoms increase the risk for later dementia in community-dwelling older adults.