As the population continues to age, the incidence of dementia and Alzheimer's disease (AD) is dramatically increasing, resulting in an urgent need to identify those older adults at risk for unhealthy brain aging and dementia. Mild cognitive impairment (MCI) is a well-accepted prodromal phase of AD. Because as many as 60% of individuals with MCI convert to AD within a three-year period, early identification of MCI is becoming increasingly important. Unfortunately, estimates suggest that at least half of individuals with MCI go undiagnosed in the community. Many barriers at the primary care level are associated with under-diagnosis of MCI, including insufficient time to assess cognition and lack of efficient screening tools available for use in primary care. To overcome these barriers, the current study will examine the nature of cognitive complaints within the community in order to develop a valid and reliable cognitive complaint measure for community-based older adults. Information from the proposed study will provide a cost-effective and time-efficient tool to aid in assessment and referral decisions for primary care patients in need of a more comprehensive memory work- up. Using a case-control cohort, we will validate a set of questions that reliably measure cognitive complaint with respect to differential diagnosis and in relation to objective cognitive performance, neuroanatomical changes, and biomarker levels. Mentored training activities will focus on latent variable modeling, neuroimaging principles in aging research, clinical implementation of psychological tools within the community, and professional development. The proposed study and training will leverage an interdisciplinary team (including neuropsychology, geriatrics, neurology, neuroradiology, and biostatistics) as well as resources associated with the Vanderbilt Memory & Alzheimer's Center, the Vanderbilt University Institute of Imaging Science, and the Vanderbilt University Department of Biostatistics to fulfill the aims outlined.