How Do Cognitively Normal Adults Understand Elevated Brain Amyloid Results?
Implications
The results suggest that some people who are cognitively normal but have subjective memory concerns “will use an Alzheimer’s disease biomarker test to explain their memory concerns, potentially pathologizing normal and nondisease-related cognitive aging,” the researchers said. In addition, people without a family history of Alzheimer’s disease or subjective memory concerns “may be unprepared to receive their biomarker results.”
A desire for more specific and detailed information about the results may be especially relevant to cognitively normal adults. “Such specific information is likely less relevant for symptomatic individuals who receive a binary result that either confirms or rules out a diagnosis that explains their history of cognitive decline,” the researchers said.
Because most participants were highly educated and had a family history of Alzheimer’s disease, the applicability of the results to other populations is limited. In future studies, the researchers plan to assess how elevated versus not-elevated brain amyloid results influenced SOKRATES participants’ sense of self, social relationships, and behaviors.
Potential Interventions and Ethical Concerns
The long prodromal period of Alzheimer’s disease “represents our greatest hope for effective therapeutic intervention as well as a domain of serious ethical concern,” said Winston Chiong, MD, PhD, of the Memory and Aging Center, Weill Institute for Neurosciences, University of California, San Francisco, in an accompanying editorial. “Prevailing appropriate use criteria advise against clinical use of amyloid imaging in asymptomatic individuals, citing ‘a significant potential for patients and families to make inaccurate assumptions about risk and future outcomes on the basis of amyloid PET results.’” The A4 trial, however, “not only requires that amyloid imaging be performed but also effectively requires that the results of such imaging be disclosed to participants.”
Qualitative research may elicit unanticipated beliefs or concerns, and in SOKRATES, “a sizable proportion of participants … expressed dissatisfaction with the categorical characterization of results.”
“Overall, the findings of Mozersky and colleagues are broadly reassuring regarding research participants’ ability to understand the prognostic uncertainty of amyloid imaging. But as the authors note, caution is needed in generalizing their results,” Dr. Chiong said. “These participants represent a selected subpopulation of an already rarified group: prospective participants in the A4 study were provided with study materials for this substudy, and interested participants themselves contacted the study investigators. These participants were thus likely to be particularly supportive of the Alzheimer’s disease research enterprise, and given their family histories and high educational attainment
Suggested Reading
Chiong W. Challenges in communicating and understanding predictive biomarker imaging for Alzheimer disease. JAMA Neurol. 2018;75(1):18-19.
Mozersky J, Sankar P, Harkins K, et al. Comprehension of an elevated amyloid positron emission tomography biomarker result by cognitively normal older adults. JAMA Neurol. 2018;75(1):44-50.
