Alzheimer’s Disease Dramatically Accelerates Cognitive Decline

Rush University Medical Center (Illinois, USA) researchers find that people with Alzheimer's disease experience a rate of cognitive decline four times greater than those with no cognitive impairment.  Robert S. Wilson and colleagues followed 1,168 older adults, enrolled in the Chicago Health and Aging Project, a longitudinal cohort study of older white and black persons residing on the south side of Chicago. At the study’s start, none of the subjects had dementia. After a mean of five to six years, subjects underwent a detailed clinical evaluation, from which 614 subjects were found to have no cognitive impairment, 395 had mild cognitive impairment, and 149 had Alzheimer's disease. The subjects then completed brief cognitive testing at 3-year intervals for a mean of five and half years. In comparison to the no cognitive impairment group, the annual rate of cognitive decline was increased more than twofold in those with mild cognitive impairment and more than fourfold in those with Alzheimer's disease. The results did not vary by race, sex, or age. The team writes that: “Alzheimer disease has a devastating impact on cognition, even in its prodromal stages, with comparable effects in African American and white persons.”