Late-Life Depressive Symptoms and Lifetime History of Major Depression: Cognitive Deficits are Largely Due to Incipient Dementia rather than Depression

Article type: Research Article

Authors: Heser, Kathrin^{a; *} | Bleckwenn, Markus^b | Wiese, Birgitt^c | Mamone, Silke^c | Riedel-Heller, Steffi G.^d | Stein, Janine^d | Lühmann, Dagmar^e | Posselt, Tina^e | Fuchs, Angela^f | Pentzek, Michael^f | Weyerer, Siegfried^g | Werle, Jochen^g | Weeg, Dagmar^h | Bickel, Horst^h | Brettschneider, Christianⁱ | König, Hans-Helmutⁱ | Maier, Wolfgang^{a; j} | Scherer, Martin^{e; 1} | Wagner, Michael^{a; j; 1} | for the AgeCoDe Study Group

Affiliations: [a] Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany | [b] Department of General Practice and Family Medicine, University of Bonn, Bonn, Germany | [c] Working Group Medical Statistics and IT Infrastructure, Institute of General Practice, Hannover Medical School, Hannover, Germany | [d] Institute of Social Medicine, Occupational Health and Public Health, University of Leipzig, Leipzig, Germany | [e] Department of Primary Medical Care, University Medical Center Hamburg-Eppendorf, Hamburg, Germany | [f] Institute of General Practice, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany | [g] Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany | [h] Department of Psychiatry, Technical University Munich, Munich, Germany | [i] Department of Health Economics and Health Services Research, Hamburg Center for Health Economics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany | [j] DZNE, Center for Neurodegenerative Diseases, Bonn, Germany

Correspondence: [*] Correspondence to: Kathrin Heser, PhD, Department of Psychiatry and Psychotherapy, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany. Tel.: +49 228 287 19827; Fax: +49 228 287 90 19827; E-mail: Kathrin.Heser@ukb.uni-bonn.de.

Note: [1] shared last authorship.

Abstract: Background: Late-life depression is frequently accompanied by cognitive impairments. Objective: Whether these impairments indicate a prodromal state of dementia, or are a symptomatic expression of depression per se is not well-studied. Methods: In a cohort of very old initially non-demented primary care patients (n = 2,709, mean age = 81.1 y), cognitive performance was compared between groups of participants with or without elevated depressive symptoms and with or without subsequent dementia using ANCOVA (adjusted for age, sex, and education). Logistic regression analyses were computed to predict subsequent dementia over up to six years of follow-up. The same analytical approach was performed for lifetime major depression. Results: Participants with elevated depressive symptoms without subsequent dementia showed only small to medium cognitive deficits. In contrast, participants with depressive symptoms with subsequent dementia showed medium to very large cognitive deficits. In adjusted logistic regression models, learning and memory deficits predicted the risk for subsequent dementia in participants with depressive symptoms. Participants with a lifetime history of major depression without subsequent dementia showed no cognitive deficits. However, in adjusted logistic regression models, learning and orientation deficits predicted the risk for subsequent dementia also in participants with lifetime major depression. Conclusion: Marked cognitive impairments in old age depression should not be dismissed as “depressive pseudodementia”, but require clinical attention as a possible sign of incipient dementia. Non-depressed elderly with a lifetime history of major depression, who remained free of dementia during follow-up, had largely normal cognitive performance.

Keywords: Cognition, dementia, depression, depressive symptoms, executive function, memory

DOI: 10.3233/JAD-160209

Journal: Journal of Alzheimer's Disease, vol. 54, no. 1, pp. 185-199, 2016