MILD COGNITIVE IMPAIRMENT: AGING TO ALZHEIMER'S DISEASE

MILD COGNITIVE IMPAIRMENT: AGING TO ALZHEIMER’S DISEASE Edited by Ronald C. Petersen 2003. Oxford: Oxford University Press Price: £39.50. ISBN 0‐19‐512342‐5This is an interesting, thought‐provoking, sometimes controversial and eminently readable book. Mild cognitive impairment (MCI) refers to the borderland between normal ageing and dementia. The term MCI has recent origins, having been introduced only in the last decade in recognition of the fact that the onset of dementia is insidious. There is a prodromal phase during which an individual functions at a lower level than normal, yet the changes in cognition are insufficient to warrant a classification of dementia. Herein lies a fundamental conceptual difference between MCI and descriptive labels that acquired prominence in earlier decades, such as ‘benign senescent forgetfulness’ and ‘age‐associated memory impairment’. These latter terms implied changes in memory, which were thought to be largely consistent with and the product of normal ageing. MCI, by contrast, is construed as abnormal ageing and commonly thought of as the prodrome to dementia, more specifically to Alzheimer’s disease.MCI raises a variety of conceptual issues. If MCI is cognitive impairment in excess of that expected in normal ageing, what is the yardstick for defining normal ageing? Within a lifetime, a variety of adverse events, lifestyle factors and age‐related medical conditions might potentially influence cognitive function. Studies of ‘normal’ ageing that adopt a rigorous policy of excluding from the study sample people with any potential risk factor whatever (e.g. the presence of diabetes or a history of alcohol consumption) risk identifying a population of ‘supernormals’ whose performance is unrepresentative of the ageing population as a whole. The implication of an overly …