You’re about to turn 60, and you’re fretting. Your mother has had Alzheimer’s disease since the age of 65. At what age will the disease strike you? A Canadian study published in JAMA Neurology shows that the closer a person gets to the age at which their parent exhibited the first signs of Alzheimer’s, the more likely they are to have amyloid plaques, the cause of the cognitive decline associated with the disease, in their brain.