By combing through dozens of Alzheimer’s disease (AD) studies, psychologists have gained a clear picture of cognitive problems in people who will develop the degenerative brain disease. The meta-analysis reveals that people can show early warning signs across several cognitive domains years before they are officially diagnosed, confirming that Alzheimer’s causes general deterioration and tends to follow a stable preclinical stage with a sharp drop in function. The findings appear in the July issue of Neuropsychology, which is published by the American Psychological Association.Researchers at the Karolinska Institute and Stockholm Gerontology Research Center, affiliated also with the Max Planck Institute for Human Development and the University of South Florida, crunched the data from a decade’s worth of studies: Published reports that met stringent criteria had records on 1,207 people with preclinical Alzheimer’s (they later developed the disease) and 9,097 controls who stayed healthy.
