GENE TESTING ISN'T RECOMMENDED FOR MOST PEOPLE
    Alice's type is even more rare; she tells her three adult children in the movie: "It's familial. It's passed on genetically."
    With this autosomal dominant form of young Alzheimer's, inheriting one of three genes with particular mutations leads to the disease. Children of an affected parent have a 50 percent chance of having inherited the family's culprit mutation. As in other families, Alice's children have to grapple with whether they want to be tested to find out.
    But the vast majority of Alzheimer's isn't linked to a particular bad gene. There are various genes that can increase the risk, but people who never develop dementia symptoms can carry them, too. That's why medical guidelines don't recommend genetic testing for the average person.
MANY SYMPTOMS ARE UNIVERSAL REGARDLESS OF AGE OF ONSET
    "I can see the words hanging in front of me and I can't reach them, and I don't know who I am or what I'm going to lose next," Alice says.
    To help with the movie's first-person perspective, Carrillo's group put actress Moore in touch with someone in the earlier stages of Alzheimer's who could describe how disorienting symptoms felt — that frustrating inability to retrieve a word or the fear that comes with suddenly not recognizing a familiar place.
    Forgetting a word now and then happens to lots of people. The Alzheimer's Association lists warning signs that may distinguish between normal forgetfulness and something you should discuss with a doctor. On the worry list: memory loss that disrupts daily life, difficulty completing familiar tasks, withdrawing from social activities and personality changes.
PEOPLE MAY COMPENSATE FOR A WHILE
    If it seemed like the movie's Alice suddenly declined fast, consider a concept that neuroscientists call "cognitive reserve." People who have had more years of education are thought to have some protection because the extra learning increased connections between their brain's neurons. When Alzheimer's begins blocking those connections, the brain at first can choose an alternate route to retrieve a memory.
    "Your brain's kept buffered up," explained Carrillo. But eventually, the brain reaches a tipping point and can't compensate any longer, so "the change seems more dramatic."
    WHAT'S IN THE PIPELINE
    There is no cure for Alzheimer's, and today's treatments only temporarily ease some symptoms. Scientists aren't even sure what causes the disease, although a sticky brain protein called amyloid is one suspect.
    Nor is diagnosis simple. There is no one Alzheimer's test, but a battery of evaluations. Sometimes, doctors use PET scans to measure amyloid buildup, but only in carefully selected cases because plenty of people without Alzheimer's harbor the gunk, too.
    The Obama administration has declared a goal of finding effective Alzheimer's treatments by 2025. Research suggests Alzheimer's begins silently ravaging the brain up to 20 years before symptoms begin. One approach under study now is testing to see whether curbing sticky amyloid during that window period might at least postpone symptoms a few more years, if not prevent them.