Proposed Alzheimer’s definition offers improvements in research and diagnosis

30 April 2018 – A new research framework proposed by the US National Institute of Aging and Alzheimer’s Association could offer significant improvement in the results of clinical trials, and future diagnosis of dementia.

The framework, by leading researchers in the April edition of Alzheimer’s and Dementia, proposes a shift from the current method of diagnosis for Alzheimer’s disease that is based on evaluating symptoms and behaviour, to a biological model used in the diagnosis of other conditions such as diabetes and cancer.

The change is not recommended for primary care practice but is instead focused on enabling clinical trials to be targeted more effectively to exclude those who do not clinically have the disease - but are often recruited due to the wide range of factors and other conditions that show similar symptoms. It is hoped that the new research framework will offer a new ‘common language’ for research that could accelerate the development of disease modifying treatments in the future.

Serge Gauthier, MD, Chair of ADI’s Medical and Scientific Advisory Panel, said: “This is a very significant step forward in the early diagnosis of biological components of Alzheimer’s disease in individual patients, and will lead to a personalized approach to new treatments appropriate for each person at each disease stage”.

If proven to have prognostic validity, these biomarkers to identify Alzheimer’s disease pathology could occur far earlier than current diagnosis, which is too often made when a person has already experienced symptoms that interfere with their usual activities in daily life - symptoms such as changes in thinking, reasoning, communicating, spatial awareness or memory.

An earlier diagnosis of dementia would mean that the individual has longer to adjust to the challenges of dementia, and to benefit from support and treatment sooner. Importantly, it could be made before the symptoms of dementia are developed.

Paola Barbarino, CEO of ADI, welcomed the momentum behind the framework, stating, “This framework is an important development to help tackle what is undoubtedly the most difficult medical and scientific challenge we face. ADI welcomes this significant step but urges that developments should consider the global impact of the disease including the many communities where basic access to a current diagnosis and support, as well as clinical trials, is very limited.” 

Alireza Atri, MD, PhD, Vice-Chair of ADI’s Medical and Scientific Advisory Panel, commented: “This is a seminal conceptual research advance. It allows classification of early biological changes in the Alzheimer’s disease pathway that can now be measured, using advanced technologies, many years prior to the potential development of clinical symptoms.

The new definitions will facilitate long term research that is needed to better identify those at risk and to assess experimental treatments that may prevent Alzheimer changes from advancing to produce dementia symptoms.” 

Every three seconds someone in the world develops dementia but diagnosis remains a significant challenge for the majority of those affected. Most people with dementia live in low and middle-income countries, where access to support, and particularly research, continue to present important barriers to applying the new framework more widely. If sufficiently progressed, the implications of the new framework are far reaching for an improved, more personalised approach to diagnosis in general practise.

Alzheimer’s and Dementia is the open access Journal of the Alzheimer’s Association.

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