Summary: A $3.3 million grant from the National Institute on Aging will fund a five-year UC Davis study led by Dr. Sarah Tomaszewski Farias and Dr. Rachel Whitmer. The research will enroll roughly 4,000 racially, culturally, and socioeconomically diverse adults aged 55 and older to determine how subjective cognitive complaints predict future Alzheimer’s disease and cerebrovascular-related cognitive decline.
Key Facts
- Large, diverse cohort: Approximately 4,000 participants aged 55+ will be followed longitudinally for up to five years to map how self-reported cognitive concerns progress to objectively measurable impairment.
- Addressing representation gaps: The study specifically targets the historical underrepresentation of racially and socioeconomically diverse groups in subjective cognitive decline (SCD) research, which has often relied on highly educated, White cohorts.
- Diagnostic distinctions using ECog: The research uses the updated Everyday Cognition (ECog) scale to determine whether particular complaint patterns—such as memory versus executive function concerns—are associated with distinct brain pathologies.
- Integration of biomarkers: Self-reported complaints will be validated against structural brain imaging and plasma biomarkers associated with Alzheimer’s neuropathology and cerebrovascular brain injury.
- Re-evaluating the “worried well”: The project aims to distinguish true early neurodegenerative signals from mood-related complaints (depression or anxiety), reframing how clinicians interpret subjective reports up to five to ten years before objective decline is detectable.
Source: UC Davis
Overview
University of California, Davis Professor of Neurology Sarah Tomaszewski Farias has received a $3.3 million, five-year award from the National Institute on Aging to study how cultural, racial, and socioeconomic factors influence how older adults notice and describe changes in their thinking and memory. These personal reports are referred to as subjective cognitive decline (SCD).
Subjective cognitive decline occurs when an individual senses that their cognitive abilities are deteriorating, yet performs within normal limits on standardized neuropsychological testing. Although these complaints were often dismissed in the past as the concerns of the “worried well,” growing evidence suggests SCD can be an early indicator of future measurable cognitive decline, including mild cognitive impairment and dementia.
Challenges in current SCD research
Existing SCD literature faces three primary limitations: overlapping symptoms with depression and anxiety that can obscure diagnosis; insufficient racial and educational diversity among study participants; and a shortage of long-term, longitudinal data that track individuals over time rather than at a single point.
Tomaszewski Farias’ new project is designed to overcome these limitations by enrolling a large, diverse cohort and combining self-reported measures with objective cognitive tests, brain imaging, and blood-based biomarkers to clarify which subjective complaints carry the greatest risk for future neurological disease.
Methodology
The study will follow about 4,000 adults aged 55 and up. It will leverage a longitudinal cohort from the UC Davis Alzheimer’s Disease Research Center, where Tomaszewski Farias serves as clinical core leader, along with three Kaiser Permanente cohorts coordinated by Professor Rachel Whitmer (including Life After 90, KHANDLE, and STAR). Researchers will collect repeated measures of subjective and objective cognition alongside structural MRI and plasma biomarkers for Alzheimer’s and vascular pathology.
Types of subjective complaints and expected patterns
SCD is not a single uniform phenomenon; individuals report a variety of cognitive concerns. The ECog scale—originally developed by Tomaszewski Farias and colleagues and recently updated—captures complaint domains such as memory, language, spatial ability, and executive functions like multitasking and planning.
Memory-specific complaints (for example, frequent forgetting of recent events) may more closely map to early Alzheimer’s disease changes in medial temporal regions. In contrast, difficulties with executive tasks—such as processing speed, multitasking, or working memory—may be more indicative of cerebrovascular changes affecting frontal-subcortical circuits. By comparing ECog domain patterns with imaging and blood markers, investigators hope to identify which subjective reports best predict specific pathologies and future clinical decline.
Cultural context and clinical implications
Tomaszewski Farias emphasizes that how people describe cognitive changes can be shaped by cultural background, education, and expectations about aging. A one-size-fits-all approach to interpreting subjective complaints is unlikely to be accurate. The study will explore how cultural factors influence whether people label cognitive changes as worrisome or attribute them to normal aging, and how those perceptions relate to later objective outcomes.
Clinically, the goal is to improve early detection strategies: to isolate the subjective complaint types that are most predictive of Alzheimer’s disease or cerebrovascular decline, and to develop efficient screening approaches that help clinicians prioritize follow-up testing and biomarker assessment.
Key Questions Answered:
A: SCD refers to a person’s perception of a persistent decline in memory or thinking despite performing within normal limits on standardized tests. Mild cognitive impairment (MCI) is diagnosed when objective testing reveals measurable cognitive deficits.
A: Domain-specific complaints often reflect different neural systems: memory complaints commonly relate to medial temporal lobe changes seen in Alzheimer’s disease, while executive dysfunction tends to correlate with frontal-subcortical and vascular pathway disruptions typical of cerebrovascular disease.
A: Prior research has relied heavily on cross-sectional data, lacked diverse racial and educational representation, and often did not separate mood-related complaints from early neurodegenerative symptoms. This longitudinal, diverse-cohort study aims to address those gaps.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by staff.
About this cognitive decline research news
Author: Marianne Sharp
Source: UC Davis
Contact: Marianne Sharp – UC Davis
Image: Image credited to Neuroscience News