The association between late-life depression, mild cognitive impairment and dementia: is inflammation the missing link?

Abstract

Depression, mild cognitive impairment (MCI) and dementia are highly prevalent conditions that are increasing exponentially with similarly expanding social, medical and economic burdens. While there is a clear clinical connection between these three disorders, the mechanism of action that links them is less well understood. The lack of well-accepted biomarkers results in high levels of diagnostic subjectivity, which then greatly impacts research results when attempting to further explore their association. There is also a variety of clinical presentations of depressive syndromes, particularly in the elderly; each one may be associated with a different risk in the progression from MCI to different types of dementia. The diagnostic challenges, the importance of biomarkers and the discussion of inflammation as a possible link between depression, MCI and dementia are examined in this article.

Keywords::

• Alzheimer’s disease
• biomarker
• cytokine
• dementia
• depression
• inflammation
• mild cognitive impairment

Acknowledgements

The authors acknowledge the assistance of Gisella Klekamp with the design of the figures.

Financial and competing interests disclosure

WM McDonald is supported by Health Resources and Services Administration grant (6UB4HP19215). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.