Though symptoms are similar, early onset affects those in their 30s, 40s or 50s. It is marked by a swift decline that, often within five years of diagnosis, strips young, healthy men and women of their jobs, their sexuality and their ability to care for their children. Victims usually progress to the terminal stage within 10 years.

The Three Stages

Early: Symptoms may include mild forgetfulness, difficulty concentrating, depression, withdrawal from usual activities.

Middle: Symptoms may include forgetting personal history, an inability to recognize family or friends, confusion to the point of needing help bathing and dressing, restlessness, delusions.

Late: Symptoms may include loss of ability to speak, inability to control the bladder and bowels, sleeping longer and more often, severe disorientation about time and people, difficulty eating and swallowing.

A Test

A simple test reveals the impaired brain function that can signal early onset Alzheimer's: Say a string of four numbers out loud and have the person repeat them back to you, but in reverse order. People can normally nail all four, but those with early onset often can't get past one or two.