When Is Alzheimer's Not Dementia—Cochrane Commentary on the National Institute on Ageing and Alzheimer's Association Research Framework for Alzheimer's Disease

Jenny Mccleery; Leon Flicker; Edo Richard; Terence J. Quinn


Age Ageing. 2019;48(2):174-177. 

In This Article

No Disease is an Island

The framework applies only to AD and all other potential contributors to cognitive decline are lumped together as 'suspected non-Alzheimer pathologic change'. It is now possible to identify growing number of pathologies which may affect the aging brain, but we have only very limited understanding of what initiates these pathologies, how they are related to each other, how they develop over time and how they relate to cognitive decline. Many would argue that the focus on AD in this guidance is overly reductionist. Dementia processes are not always separate and distinct. Many patients do not fit neatly within a single disease category and complexity is the rule rather than the exception. Too exclusive a focus on one type of pathology may discourage research on the interaction between different pathological processes, an approach which could open up much-needed new therapeutic avenues. Further, the idea that early intervention trials will inevitably be improved by delineating a population of people with homogeneous underlying neuropathology is open to question, since the external validity of such trials will be limited.