Predicting Symptom Onset in Sporadic Alzheimer's Disease: "How Long Do I Have?"

Predicting not just if but when cognitively normal individuals will develop the onset of Alzheimer's disease (AD) dementia seems increasingly feasible, as evidenced by converging findings from several approaches and cohorts. These estimates may improve the efficiency of clinical trials by better identifying cognitively normal individuals at high risk of developing AD symptoms. As models are refined, the implications of disclosing estimates of the age of AD symptom onset must be examined, since telling a cognitively normal individual the age they are expected to develop AD symptoms may have different implications than disclosing increased risk for AD dementia.