Does alzheimer's disease occur in younger adults too?

Not usually: Alzheimer's disease occurs in a few patients starting in their 40's or 50's though it is most common in older adults. Far less then 1% of people younger than age 65 have the illness while 1% of those aged 65 do and nearly half of those aged 85 and older have it. There are changes in the brains of many of us at a younger age than this but no clinical symptoms.

It is rare: There are rare forms of early-onset Alzheimer's disease that run in families. These forms of Alzheimer's disease are usually cause by mutations in one of three genes. People with these mutations often develop Alzheimer's disease in their 40s and 50s. Families with multiple people suffering from early-onset Alzheimer's disease may wish to consider genetic testing.