Background: It is generally accepted that depression can be associated with significant cognitive deficits and that depression can be comorbid with dementia. Objective: This review seeks to go further and ask whether depression earlier in life can be a risk factor for subsequent dementia or for cognitive decline. Methods: A review was made of the epidemiological evidence from case-control and prospective studies that depression is a risk factor. The literature was also reviewed in relation to six hypotheses that might explain an association: (1) depression treatments are a risk factor for dementia, (2) dementia and depression share common risk factors, (3) depression is a prodrome of dementia, (4) depression is an early reaction to cognitive decline, (5) depression affects the threshold for manifesting dementia, and (6) depression is a causal factor in dementia. Results: A meta-analysis found that depression was associated with an increased risk of subsequent dementia in both case-control studies (95% CI for relative risk: 1.16–3.50) and prospective studies (95% CI: 1.08–3.20). There was little support for hypotheses 1 and 2. The other hypotheses have limited support, but warrant further research. Conclusion: There is sufficient evidence to take seriously the possibility that depression is a risk factor for dementia and cognitive decline. Further work is needed to examine depression as a prodrome of vascular dementia, depression as an early reaction to perceived cognitive decline, the effects of depression on the threshold for manifesting dementia, and depression as a source of hippocampal damage through a glucocorticoid cascade.

Keywords:
Depression, Dementia, Alzheimer’s disease, Vascular dementia, Cognitive decline, Risk factors
This content is only available via PDF.
© 2000 S. Karger AG, Basel
2000
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.