Neuropsychological Signs of Alzheimer's Disease 8 Years Prior to Diagnosis Journal of Alzheimer's Disease, 2012 Dec 19. Schmid NS, Taylor KI, Foldi NS, Berres M, & Monsch AU. Abstract We investigated the earliest neuropsychological changes in Alzheimer's disease (AD) by comparing the baseline performance of 29 individuals who subsequently developed AD within an average of 7.91 ± 2.70 years with 29 pairwise-matched individuals who remained cognitively healthy (NC). We hypothesized that subtle, qualitative changes in cognition precede clinical AD by several years, and therefore examined subjective as well as standard quantitative measures of cognition, in addition to subjective estimates of mood and medical status. Participants were selected from the 825 members of the longitudinal BASEL study (BAsel Study on the ELderly), all of whom had been ApoE-genotyped and received comprehensive bi-annual neuropsychological assessments. Within 13 years, 29 were diagnosed with p...