Depression and the Risk of Alzheimer Disease
ABSTRACT Background: Several epidemiologic studies have examined depression as a risk factor for Alzheimer disease with conflicting results. Most studies relied on self-reported depression, but the agreement between self-reported depression and clinical diagnosis has been reported to be weak, thereby diluting the association.
Methods: A population-based cohort in Odense, Denmark, of 3346 persons age 65-84 years was examined at baseline (1992-1994) and after 2 years (1994-1996) and 5 years (1997-1999). History of depression was collected at baseline as self-report. We used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
Results: Persons with a history of depression had an increased risk of Alzheimer disease both at baseline (OR = 1.7; CI = 1.0-2.7) and at follow up (at 2 years, 1.9 [1.0-3.3] and at 5 years, 1.6 [0.9-2.7]).
Conclusions: Depression was associated with an increased risk of Alzheimer disease. The odds ratios were lower than generally reported from follow-up studies and are similar to cross-sectional studies.
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ABSTRACT: Background Whether depression is a long-term risk factor for dementia or represents a dementia prodrome is unclear. Therefore, we examined the relationship between depressive symptoms and dementia during short and long follow-up in a population-based cohort. Methods In the Rotterdam Study, 4393 nondemented individuals were followed for incident dementia for 13.7 years by continuous monitoring. Cox proportional hazards models for different time intervals were used to estimate the risk of incident dementia. Results Five-hundred eighty-two participants developed dementia during 13.7 years. Persons with depressive symptoms had an 8% increased risk of dementia compared with those without depressive symptoms during the overall follow-up. The risk was highest in the short and intermediate follow-up, particularly in men. We did not find an association in the follow-up period beyond 10 years. Conclusion Our results suggest that late-life depressive symptoms are part of a dementia prodrome rather than an independent risk factor of dementia.Alzheimer's & dementia: the journal of the Alzheimer's Association 10/2014; DOI:10.1016/j.jalz.2013.10.006 · 17.47 Impact Factor
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ABSTRACT: Background Many of the symptoms, consequences, and risk factors for frailty are shared with late-life depression. However, thus far, few studies have addressed the conceptual and empirical interrelationships between these conditions. This review synthesizes existing studies that examined depression and frailty among older adults and provides suggestions for future research.MethodsA search was conducted using PubMed for publications through 2010. Reviewers assessed the eligibility of each report and abstracted information on study design, sample characteristics, and key findings, including how depression and frailty were conceptualized and treated in the analysis.ResultsOf 133 abstracted articles, 39 full-text publications met inclusion criteria. Overall, both cross-sectional (n = 16) and cohort studies (n = 23) indicate that frailty, its components, and functional impairment are risk factors for depression. Although cross-sectional studies indicate a positive association between depression and frailty, findings from cohort studies are less consistent. The majority of studies included only women and non-Hispanic Whites. None used diagnostic measures of depression or considered antidepressant use in the design or analysis of the studies.ConclusionsA number of empirical studies support for a bidirectional association between depression and frailty in later life. Extant studies have not adequately examined this relationship among men or racial/ethnic minorities, nor has the potential role of antidepressant medications been explored. An interdisciplinary approach to the study of geriatric syndromes such as late-life depression and frailty may promote cross-fertilization of ideas leading to novel conceptualization of intervention strategies to promote health and functioning in later life. Copyright © 2011 John Wiley & Sons, Ltd.International Journal of Geriatric Psychiatry 09/2012; 27(9). DOI:10.1002/gps.2807 · 3.09 Impact Factor
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ABSTRACT: Major depressive disorders (MDD) are among the most debilitating diseases worldwide and occur with a high prevalence in elderly individuals. Neurodegenerative diseases (in particular Alzheimer's disease, AD) do also show a strong age-dependent increase in incidence and prevalence among the elderly population. A high number of geriatric patients with MDD show cognitive deficits and a very high proportion of AD patients present co-morbid MDD, which poses difficult diagnostic and prognostic questions. Especially in prodromal and in very early stages of AD, it is almost impossible to differentiate between pure MDD and MDD with underlying AD. Here, we give a comprehensive review of the literature on the current state of candidate biomarkers for MDD ("positive MDD markers") and briefly refer to established and validated diagnostic AD biomarkers in order to rule out underlying AD pathophysiology in elderly MDD subjects with cognitive impairments ("negative MDD biomarkers"). In summary, to date there is no evidence for positive diagnostic MDD biomarkers and the only way to delineate MDD from AD is to use "negative MDD" biomarkers. Because of this highly unsatisfactory current state of MDD biomarker research, we propose a research strategy targeting to detect and validate positive MDD biomarkers, which is based on a complex (genetic, molecular and neurophysiological) biological model that incorporates current state of the art knowledge on the pathobiology of MDD. This model delineates common pathways and the intersection between AD and MDD. Applying these concepts to MDD gives hope that positive MDD biomarkers can be successfully identified in the near future.Progress in Neurobiology 08/2011; 95(4):703-17. DOI:10.1016/j.pneurobio.2011.08.001 · 10.30 Impact Factor