Later Life Depressive Symptoms Not Linked With Amyloid Accumulation
In older adults with normal cognition, depressive symptoms were not consistently associated with amyloid pathology. Meanwhile, depressive symptoms were associated with a reduced likelihood of amyloid pathology in older adults with mild cognitive impairment (MCI). Researchers published their findings in JAMA Psychiatry.
“Mechanisms other than amyloid accumulation may commonly underlie depressive symptomatology in later life,” wrote first author Wietse A. Wiels, MD, of Vrije Universiteit Brussel, Brussels, Belgium, and study coauthors.
The study aimed to clarify the relationship between depression and amyloid pathology in older adults, a population in whom depressive symptoms are associated with cognitive decline. A better understanding of the mechanisms underlying depression and cognitive decline could help inform diagnostic and therapeutic intervention, researchers explained.
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The study used data across 49 centers from the Amyloid Biomarker Study data pooling initiative. Analyses included 9746 adults with normal cognition and 3023 adults with MCI with data on amyloid biomarkers, depressive symptoms, and age.
Among participants with normal cognition, the mean age was 68.6 years, 34.0% were APOE ε4 carriers, 9.6% had depressive symptoms, and 27.2% had amyloid pathology. Researchers reported a 1.13 odds ratio for amyloid pathology with the presence of depressive symptoms.
Among participants with MCI, the mean age was 70.2 years, 44.8% were APOE ε4 carriers, 27.3% had depressive symptoms, and 55.8% had amyloid pathology. The odds ratio for amyloid pathology with the presence of depressive symptoms was 0.73, according to the study.
Subgroup analyses showed a 5% higher frequency of amyloid pathology in adults with normal cognition who were APOE ε4 noncarriers but not in those who were APOE ε4 carriers. “This was not the case,” researchers wrote, “in individuals with MCI.”
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