ABSTRACT. Background and Aims: Some prospective studies show that depression is a risk factor for cognitive decline. Thus far, the explanation for the background of this association remained unclear. In the present study it is investigated (1) whether depression is etiologically linked to cognitive decline; (2) whether depression and cognitive decline may be the consequence of the same underlying subcortical pathology, or (3) whether depression is a reaction to global cognitive deterioration. Methods: A cohort of 133 depressed and 144 non-depressed older persons, was followed at eight successive observations during three years. All subjects were participants of the Longitudinal Aging Study Amsterdam (LASA). Depression symptoms were measured by means of the CES-D at eight successive waves. Cognitive function (memory function, information processing speed and global cognitive functioning) was assessed at baseline and at the last CES-D measurement. Results: Our results show that the severity and duration of depressive symptoms were not associated with subsequent decline in memory functioning or global cognitive decline. There was an association between both chronic mild depression and chronic depression, and decline in speed of information processing. Conclusions: These results support the hypothesis that in older persons chronic depression as well as cognitive decline may be the consequence of the same underlying subcortical pathology.
