A fascinating story in the San Francisco Chronicle details the progress researchers are making in understanding different kinds of dementias.
Frontotemporal dementia is similar to Alzheimer's in that major sections of the brain slowly die, and eventually most patients will suffer the same memory problems and confusion that are associated with Alzheimer's. But in the early stages of the disease, the symptoms are dramatically different from Alzheimer's.
Patients will often become impulsive and lose their inhibitions. They no longer feel things like embarrassment or pride, and they have trouble thinking past the moment they're in. An ordinarily shy man might strip off all his clothes in public or suddenly yell swear words at his boss.
There's a tendency not only in popular speech, but also among even doctors, to call any kind of odd behavior in someone over 60 Alzheimer's. What this does at a deeper level is to devalue the elderly person by dropping him or her into the convenient pigeonhole called Alzheimer's, and no more attention needs to be paid to them--by doctor or family.
It ain't that simple.