Dementia cure lies in early discovery.

• Position: Alzheimer's Disease

For years, clinical trials for Alzheimer's disease unsuccessfully focused on people with dementia--a stage in the disease now considered by physicians to be too late to represent an ideal time for treatment. However, as modern medicine hones new techniques--primarily brain imaging and biomarker testing--to identify people who do not yet have clinical symptoms but are at risk for Alzheimer's, the focus in clinical trials is shifting from people with dementia to people with no symptoms but who do have imaging and biofluid signs of pathology

"Treating those with Alzheimer's disease isn't going to be about restoring people with dementia to normal cognitive function. It's going to be about preventing it in those who are at risk," explains Clifford R. Jack, professor of radiology at Mayo Medical School. Jack's research group at the Mayo Clinic, Rochester, Minn., serves as the central MRI lab for national and international observational and therapeutic studies in Alzheimer's disease. His group heads the MRI section for the Alzheimer's Disease Neuroimaging Initiative, which began in 2005.

Jack points out that physicians already have developed effective methods of testing for Alzheimer's disease, often turning up signs of its pathology a decade or two before the patient develops any clinical signs of dementia. Through advanced brain imaging and spinal taps that test for the presence of beta-amyloid in the...