The relationship between anxiety and levels of Alzheimer's disease plasma biomarkers.

Anxiety is highly prevalent in Alzheimer's disease (AD), correlating with cerebrospinal fluid/positron emission tomography biomarkers and disease progression. Relationships to plasma biomarkers are unclear. Herein, we compare levels of plasma biomarkers in research participants with and without anxiety at cognitively normal, mild cognitive impairment, and AD dementia stages. We observed significantly higher plasma tau/amyloid-β ₄₂ ratio in AD participants with anxiety versus those without, but did not observe differences at other stages or plasma biomarkers. No such relationships were evident with depression. These results support a unique pathophysiological relationship between anxiety and AD that can be reflected in plasma biomarkers, suggestive of heightened neurodegeneration.
Competing Interests: Declaration of conflicting interestsThe authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Arjun V. Masurkar is on the council for the Alzheimer's Association International Research Grants Program and the steering committee for the Alzheimer Disease Cooperative Study, both unpaid positions. All other authors have no conflict of interest to report.