Expanding our engagement with the ethical implications of changing definitions of Alzheimer’s disease

The Alzheimer’s disease (AD) research landscape is changing rapidly. What was once a clinical construct identified by a history of stereotypical signs and symptoms is being redefined as a biological continuum described by biomarkers. This changing focus raises ethical and social challenges which need to be addressed before diagnostic criteria for asymptomatic persons move from research to the clinic¹. Clinicians do not routinely diagnose patients with ‘preclinical AD’, but a series of clinical trials now are testing drugs in cognitively normal persons with gene or biomarker-defined risk². Should these demonstrate effective drug interventions, then preclinical AD will transform from a research label to a diagnosis.

Concerns have been raised about the potential psychological harm caused by learning information about Alzheimer’s disease risk. Studies of genetic susceptibility testing suggest that such information can enable individuals and families to plan and that – in controlled settings – psychological harm is uncommon³. However, other potential consequences need to be considered, including for life and health insurance coverage, employment and driving¹. We suggest this discussion should be extended to consider the implications for an individual’s social position and identity. A focus on disease stigma may be a useful starting point for this discussion. Stigma helps to understand how people identified as belonging to a ‘preclinical’ group see themselves, how they expect people to relate to them and consequently how they are socially integrated or excluded.

Stigma contributes to marginalisation and discrimination against people with AD dementia, their caregivers and families⁴. Studies have yet to examine whether stigma exists in the preclinical stage of AD. However, evidence that shows a major driver of stigma in persons with mild stage AD dementia is the threat of future cognitive decline⁵ suggests that stigma may also be experienced by persons in the preclinical stage. If this is the case, then it further emphasizes the importance of broader social and cultural framings which shape people’s fears and expectations related to a ‘preclinical diagnosis.’

Assessments of the psychological impact of AD risk information on the individual, such as depression and anxiety, may consequently be overly narrow. Research is needed to understand the experience of stigma by individuals and families, how it is felt and enacted and how people adapt to and manage information they have been given about their possible future health.