Temporal course of depressive symptoms during the development of Alzheimer disease: blowing hot and cold over depression and cognitive impairment.

# {#article-title-2} To the Editor: Wilson et al.1 consider the relationship between depression and cognitive impairment. The accompanying editorial2 outlines the difficulty of determining causality in this association and correctly states that age is a classic confounder. Wilson et al.1 did not find an increase of depressive symptoms associated with incident dementia in subjects followed up 8 to 9 years until a mean age of 82.5 years. In contrast, we found that cognitive impairment was related to depressive symptoms in 599 oldest old subjects aged 85 years at baseline during 5 years of follow-up.3,4 It is possible that the oldest old, especially when depressed, …