Among the most frustrating challenges for any health care professional are treating and alleviating the distress of an agitated patient with dementia -- especially compelling in the midst of today's unprecedented population explosion among adults over age 65. For the first time ever, people age 85 and older represent the fastest-growing segment of our population.

As we find ways to meet this challenge, we are also transforming how we think about aging. Instead of the pejorative term "senility," which implies that simply to be old is to be infirm, we refer to the ABCs of geriatric...