Prospective and retrospective memory complaints in mild cognitive impairment and mild alzheimer's disease

Current management attempts for Alzheimer's disease (AD) focus on the identification of individuals in the preclinical stage. This has led to the development of the diagnostic concept of Mild Cognitive Impairment (MCI), which applies to individuals with declining cognitive abilities but largely preserved everyday functioning. Previous findings indicate that prospective memory deficits are a sensitive marker of preclinical AD and that awareness of prospective memory failures is particularly high, based on its dependence on executive functions. Thus, the goal of this study was to evaluate the usefulness of subjective prospective versus retrospective memory complaints for an initial screening for MCI and their respective associations with executive functions. 71 healthy older adults, 27 MCI patients, and 9 patients with mild AD completed the Prospective and Retrospective Memory Questionnaire (PRMQ) and three executive functions tests. The healthy and the MCI group could not be distinguished by their level of subjective prospective or retrospective memory complaints, but the mild AD patients differed from the other groups by complaining more about retrospective than prospective memory failures. For the healthy older adults, the prospective memory complaints were correlated to an inhibition test, whereas they did not correlate with any of the executive function tests in the MCI patients. In contrast, in both groups the retrospective memory complaints were related to a task switching test. The findings are discussed with respect to differences between the three groups in cognitive abilities, attention to failures of, use of mnemonic aids for, and everyday demands of prospective and retrospective memory.