What is the life expectancy of someone with Alzheimer's?

Dana-1 asked...

My 80 yr old Mother has had Alzheimer's since age 69. How much longer can this last? She lived with my father until his death nearly four years ago. Since then, she has lived with me, my husband and two daughters.

Expert Answer

Paula Spencer Scott is the author of Surviving Alzheimer's. A Met Life Foundation Journalists in Aging fellow, she writes extensively about health and caregiving; four of her family members have had dementia.

The general rule of thumb is that someone with Alzheimer's has half the life expectancy of a peer without this disease. So the average 70- year- old woman can expect to live 16 years, but a 70-year-old with Alzheimer's has an 8-year life expectancy. Of course, there's no crystal ball of certainty, which helps explain why your mother has already outlived that statistic. Life expectancy also depends on the age at diagnosis (the later in life you're diagnosed, the less time you're expected to live) and on general health condition. You can find more information here.