In a new study, researchers found that that depression symptoms in healthy older people who have brain amyloid, a biological marker of Alzheimer’s, could trigger changes in memory and thinking over time.
The study is among the first to reveal that this link is influenced by the cortical amyloid in healthy older adults, even when depression symptoms are mild to moderate.
The research was conducted by a team from Massachusetts General Hospital (MGH).
Increasingly, Alzheimer’s disease research has focused on the preclinical stage, when people have biological evidence of AD but no or minimal symptoms, and when interventions might have the potential to prevent the future decline of older adults.
Previous research has shown an association between depression and cognitive deficits in older individuals.
In the new study, the team found that even modest levels of brain amyloid in the brain can impact the relationship between depressive symptoms and cognitive abilities.
This raises the possibility that depression symptoms could be targets in clinical trials aimed at delaying the progression of Alzheimer’s disease.
The team collected data over a seven-year period from 276 community-dwelling older adults, all participants in the landmark Harvard Aging Brain Study (HABS).
They discovered a strong link between worsening depression symptoms and declining cognition over two to seven years that was influenced by Alzheimer’s pathology, as measured by PET imaging of brain amyloid.
The findings offer evidence that in healthy older adults, depression symptoms together with brain amyloid may be linked to early changes in memory and in thinking.
The team says depression symptoms themselves may be among the early changes in the preclinical stages of dementia syndromes.
Just as importantly, these stages represent a clinical window of opportunity for closely monitoring at-risk individuals, and for potentially introducing interventions to prevent or slow cognitive decline.
The lead author of the study is Jennifer Gatchel, MD, Ph.D., of the MGH Division of Geriatric Psychiatry.
The study is published in JAMA Network Open.
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