"Aisen foresees a future — maybe just a decade or so down the line — in which much of the burden of Alzheimer’s disease might actually be prevented. “We’re heading towards screening people from middle age on with blood tests, and treating those who show amyloid abnormalities with drugs that reduce the generation of amyloid plaques,” he says. “I am optimistic.”
A lot needs to go right for this hopeful view to become reality. Large clinical trials will have to show that these therapies work, and amyloid-clearing drugs will have to be proven to be safe and affordable. After decades of setbacks and failed clinical trials, some dementia researchers prefer to express caution. “The field is taking tremendous risks by engaging in studies that can cost billions of dollars,” says neurologist David Knopman at the Mayo Clinic in Rochester, Minnesota.
It will take a while for answers to emerge. Some trials of Alzheimer’s disease prevention are just getting started, and some ongoing ones could stretch into the next decade."