Do severity and duration of depressive symptoms predict cognitive decline in older persons? Results of the Longitudinal Aging Study Amsterdam

Abstract

ABSTRACT. Background and aims: INTRODUCTIONProspective studies concerning the question whether late life depression is associated with subsequent cognitive decline have yielded conflicting results (1-8). However, there is sufficient evidence to assume that depression is a risk factor for cognitive decline (7). So far, the explanation for the background of this association has remained unclear.The pathological effect of depression on cognitive function may be caused by high levels of glucocorticoids (cortisol). Secretion of glucocorticoids plays a central role in the short-term biological adaptation to stress. However, prolonged stress and prolonged exposure to hypersecretion of glucocorticoids may have adverse (neurotoxic) effects on the brain, particularly the hippocampus (9, 10), which plays a critical role in memory function, especially in the consolidation of short-term into long-term explicit memory, but also in the encoding of new information (11). Therefore, the severity and duration of depressive symptoms may lead to impairment of memory function.There are two other explanations for the association between depression and cognitive decline. First, a common underlying organic pathology, for instance, in white matter and other subcortical abnormalities (12), may cause depression as well as cognitive decline in elderly respondents. Second, depression may be considered as a psychological reaction to eroding cognitive capacities early in the course of dementia (4).In our former study (8), we investigated these three hypotheses on the association between late life depression

The Association of Self-Reported Sleep Duration, Difficulty Sleeping, and Snoring With Cognitive Function in Older Women

“…First, we specifically excluded women reporting clinically diagnosed depression, possibly excluding those who are most at risk. However given the strong inter-relationships between the sleep, depression, and cognitive function, 28,29 it is difficult to adequately control for potential confounding (including severity of depression, treatment of depression). Thus we were concerned about the substantial issues involved in validly examining sleep and cognition among depressed women without highly detailed data; moreover, we did not have enough women with clinically diagnosed depression to conduct separate analyses in this subgroup.…”

Cognitive decline and dementia in diabetes—systematic overview of prospective observational studies

“…Second, depression occurs more frequently in people with diabetes [73] and is difficult to differentiate clinically from dementia and early cognitive decline [74][75][76][77]. However, at least one of the studies [54] reported an association between diabetes and cognitive decline even after adjustment for depression.…”

Depressive Symptoms, Major Depressive Episode and Cognition in the Elderly: The Three-City Study

“…There is an abundant literature on the relationship between depression and cognitive decline or dementia [25][26][27][28][29][30][31][32][33][34] . A majority of studies used the CES-D scale to define depressed individuals and they concluded that depression is a risk factor for dementia for most of them (7 out of 8).…”