Commentary

Abstract

Dubois, Gauthier, and Cummings argue strongly and coherently for the need for revision of the Alzheimer's diagnostic accuracy and the many benefits to moving to a new diagnostic system. What they propose represents a fundamental paradigm shift in our field, moving Alzheimer's disease from a clinic-pathological to a clinic-biological entity, and separating the diagnosis of Alzheimer's disease from Alzheimer's dementia. In other words, recognising that people can have Alzheimer's disease for many years before they develop the global cognitive decline needed to fulfil current clinical criteria for dementia. The new diagnostic criteria are strongly supported by a very large body of research over the last 25 years and seek to advance the previous McKhann et al. (1984) criteria by, in particular, enhancing diagnostic specificity since, for the first time, CSF and imaging biomarkers are needed to “rule in” rather than simply rule out other disorders. The authors emphasise that these are research criteria and that they require validation and further investigation of clinical utility, whilst also pointing out that they have already been implemented in current Phase 2 clinical studies. Such a parallel introduction of criteria to our field whilst validation is ongoing is nothing new for psychiatry, or indeed dementia, and the same happened for the original Alzheimer's disease criteria as well. Dubois, Gauthier, and Cummings end with a stated aspiration to move the criteria from research to clinical settings, and by doing so hopefully increase the accuracy of the clinical diagnosis of Alzheimer's disease and ultimately improve patient care.