Alzheimer's Disease is more than just memory loss. While the symptoms may include the "where did I put my keys" problem, the disease interrupts brain function and eventually causes death.

The course of Alzheimer's disease is not the same in every person, but symptoms seem to increase over the same general stages. In most people with Alzheimer's, symptoms first appear after age 60.

Scientists have found that Alzheimer's progresses on a spectrum with three stages-an early, pre-clinical stage with no symptoms; a middle stage of mild cognitive impairment or (MCI); and a final stage of Alzheimer's dementia. At this time, doctors cannot predict with any certainty which people with MCI will or will not develop Alzheimer's.

The good news for people that will be diagnosed in the future is the enormous amount of resources pharmaceutical manufacturers are committing to finding treatments. After more than two decades of research, a treatment that slows or actually reverses the progression of Alzheimer's has proven elusive, in part because researchers still have not pinpointed the cause of the disease.

The need for an effective treatment is massive and growing. Dementia affects 5 million-plus people in the U.S. and over 35 million worldwide, according to Alzheimer's Disease International. With the global population aging, those numbers are expected to triple by 2050.

The handful of Alzheimer's drugs on the market, approved more than a decade ago, treat the symptoms of cognitive decline. They include Aricept from Pfizer, Namenda from Forest Laboratories and Exelon from Novartis. Their combined sales last year just topped 6 billion dollars.