Preclinical Alzheimer Disease-Early Diagnosis or Overdiagnosis?

This Viewpoint argues that the shift from treating patients with symptomatic Alzheimer disease to treating those with preclinical disease carries the risk of overdiagnosis.

The results of clinical trials of new treatments for Alzheimer disease (AD) have been consistently disappointing. Treatment failures for symptomatic individuals with mild cognitive impairment (MCI) or dementia due to AD combined with growing evidence of a perhaps decades long presymptomatic stage of AD have led to a focus on preventive treatments for high-risk individuals prior to any symptom onset. The hope is that treatment of preclinical AD, which is defined as the presence of AD brain pathology without evidence of cognitive impairment, will be the breakthrough that keeps older adults' memories and independence intact.