Demystifying the Mystery of Alzheimer's as Late, No Longer Mild Cognitive Impairment

Professor Tom Kirkwood and Michael Bavidge's comments are welcome additions to our discourse as both emphasize the importance of considering mild cognitive impairment (MCI) and Alzheimer's disease (AD) in relationship to the normal biological and cultural processes of aging. Whereas I agree with my colleague and co-author, Atwood Gaines' response, I wish to add my own commentary to update the reader concerning the dynamic political processes at work in the social construction and deconstruction of MCI and AD. I have referred to MCI as autodeconstructing AD because whatever we come to think of the MCI label on the spectrum of cognitive aging should alter our beliefs about the ultimate utility of the concept of AD. Tensions in the field of study of MCI have increased since the project reported in this journal began. The social science and philosophical contributions toward understanding MCI need to inform our debate now; otherwise, we will be less effective at influencing a critical debate for society about its relationships to medicine, science, and modern capitalism.

This past year, Ron Petersen, the major proponent of the concept of MCI was awarded the prestigious Potamkin Prize for research in Alzheimer's disease by the American Academy of Neurology. The National Institute on Aging (NIA) placed the discovery of MCI as first on the list of contributions during twenty years of research funded through hundreds of millions of dollars poured into the NIA Alzheimer's Research Centers. Some have even suggested that we relabel MCI of the amnestic type, Petersen syndrome. Yet, John Morris, who was co-awarded the Potamkin Prize, has continued to write that MCI is early AD and most recently has suggested (Morris 2006) that we should revise our diagnostic criteria. He joins me and a growing list of other so-called thought leaders who believe (but do not always state publicly) that the term MCI is not useful clinically. Lon Schneider (2005) has recently joined the camp of critics publicly by suggesting that MCI is not only confusing clinically but is now possibly retarding research.

The proliferation of different kinds of MCI indicates that we are studying heterogeneous processes of brain aging. Whereas, John Morris suggests that we relabel MCI as early AD, I have suggested the converse. For example, in a grand rounds lecture at Johns Hopkins in March 2004, I used the lecture title "LNLMCI (late no longer MCI)" as a synonym for AD.

Kirkwood is right to compare the quest for biological therapy for AD to the search to treat aging processes in other organs. He has been an outspoken critic of anti-aging medicine quackery that claims that aging itself is a disease that can be reversed today. But, if AD is brain aging, are we not in fact creating a "disease" category that raises false hopes and expectations?

Kirkwood also points out that aging is a lifespan process. To prevent dementia in older individuals, we should prevent damage to neurons in younger individuals. Recently, it has been claimed, for example, that exposure to lead in young animals makes these animals more at risk for amyloid deposition in later life (Basha et al. 2005). Whether or not lead directly affects the pathogenesis of AD, it seems eminently reasonable to try to prevent damage to neurons in young children so that they may have maximum cognitive capacity throughout their lifespan.

Almost ten years ago, when I stepped down as the editor of the Alzheimer's Disease and Associated Disorders Journal and as John Morris took over this responsibility, I wrote an editorial calling for the end of AD (Whitehouse 2001). In other words, I argued that thinking through the invention of the term mild cognitive impairment reveals that we are attempting to assign medical categories to what are a heterogeneous set of processes that affect our brains as we age. At the hundredth anniversary of the first case of what we have come to call Alzheimer's disease, perhaps it is time to reflect on the individual and social...