Alzheimer’s at the Crossroads
STOCKHOLM – “Perfect health, like perfect beauty, is a rare thing; and so, it seems, is perfect disease,” said Peter Latham, a nineteenth-century English physician. Alzheimer’s disease (AD) is certainly no exception: changes in the brain occur decades before symptoms begin to show; there is no validated biological diagnostic test; and there are only imprecise measures of correlation between AD’s clinical and neuropathological progression. There is no cure yet, but, unlike just ten years ago, treatment of its symptoms is now widely available.
Alzheimer’s has again come to a crossroads. Diagnostic criteria have not been updated in nearly two decades, but this is about to change. New versions of the International Classification of Diseases (ICD-11) and Diagnostic and Statistical Manual of Mental Disorders (DSM-V) are planned for 2013-2014, and proposals for revising the definition of AD have recently been published.
AD is currently diagnosed late, in the stage of dementia characterized by cognitive impairments so severe that they undermine social and occupational functioning. When significant irreversible brain damage has already occurred, the benefits of any medication are limited at best. Thus, the dementia requirement for diagnosing AD is one important contributor to the failure of many drug trials, and also to the frustration of many patients who are impaired but not yet demented.