Commentary on “Diagnosis of Alzheimer's disease: Two decades of progress”

A n d m b n s ( 9 t a M a Dr. Zaven Khachaturian has provided an excellent acount of the history of Alzheimer’s disease (AD) research in he world, particularly in the United States, in the last few ecades. His perspective is unique because he was instruental in many of the key activities that took place during his time. I am not entirely certain that he did not also have role in Kraeplin’s decision to name the disease after Alois lzheimer in 1910. The role of the National Institute on Aging (NIA) in this volutionary process has been quite significant through the evelopment of the Alzheimer’s Disease Centers program s well as through several other key initiatives including the lzheimer’s Disease Patient Registries, Alzheimer’s Disase Cooperative Study, and the recent Alzheimer’s Disease euroimaging Initiative. I would like to comment on 2 ssues raised by Dr. Khachaturian regarding this period in istory: (1) the characterization of “normal” aging and (2) he emphasis on an earlier diagnosis of the AD process, in articular, mild cognitive impairment (MCI). Many investigators typically state that the condition they re studying differs from normal aging. However, in reality, ne area that we have not addressed adequately concerns the haracterization of the cognitive changes of normal aging. his remains a significant challenge for us, because many of ur investigations are contingent on this distinction. For xample, as I will discuss below, the construct of MCI is redicated on the differentiation of cognitive changes of ormal aging from the very early impairments seen in MCI. owever, it is equally important to distinguish MCI from arly AD, and both of these demarcations present prominent hallenges. On the normal aging boundary, we need to know “How uch forgetfulness is too much?” Most investigators beieve that some loss of cognitive efficiency is typical for