Citations

ObjectiveTo evaluate the degree to which longitudinal stability of subsyndromal symptoms of depression (SSD) is associated with conversion to dementia in patients with mild cognitive impairment (MCI).MethodsData from 405 MCI participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) study were analyzed. Participants were evaluated at baseline and 12‐month intervals over 3 years. Participants were designated as MCI converters if dementia was diagnosed within 3 years or as cognitively stable MCI if dementia was not diagnosed during this interval. SSD were evaluated utilizing the 15‐item Geriatric Depression Scale (GDS). Endorsement of specific SSD at baseline and the stability of SSD over 36 months were compared between the two MCI groups.ResultsBaseline symptom endorsement and stability of total GDS scores did not differentiate MCI groups. Worsening of four individual items from the GDS over time (memory problems, feelings of helplessness, loss of interest, and preference for staying at home) differentiated MCI converters from cognitively stable MCI (p < 0.05 for all). However, only increased endorsement of memory symptoms over time was associated with progression to dementia after controlling for other clinical variables (p = 0.05).ConclusionsSSD in MCI participants largely consist of cognitive symptoms and activity limitations, and the stability of SSD over time differentiated the MCI groups better than baseline endorsement of symptoms. However, the only significant predictor of conversion to dementia was increased endorsement of memory problems, which likely represents insight into cognitive problems more than depressive symptomatology in MCI individuals. Copyright © 2011 John Wiley & Sons, Ltd.

The pathophysiological process of Alzheimer's disease (AD) is thought to begin many years before the diagnosis of AD dementia. This long “preclinical” phase of AD would provide a critical opportunity for therapeutic intervention; however, we need to further elucidate the link between the pathological cascade of AD and the emergence of clinical symptoms. The National Institute on Aging and the Alzheimer's Association convened an international workgroup to review the biomarker, epidemiological, and neuropsychological evidence, and to develop recommendations to determine the factors which best predict the risk of progression from “normal” cognition to mild cognitive impairment and AD dementia. We propose a conceptual framework and operational research criteria, based on the prevailing scientific evidence to date, to test and refine these models with longitudinal clinical research studies. These recommendations are solely intended for research purposes and do not have any clinical implications at this time. It is hoped that these recommendations will provide a common rubric to advance the study of preclinical AD, and ultimately, aid the field in moving toward earlier intervention at a stage of AD when some disease‐modifying therapies may be most efficacious.

The fourth Leon Thal Symposium (LTS2010) was convened in Toulouse, France, on November 3, 2010. This symposium reviewed design parameters that are necessary to develop comprehensive national databases on healthy aging. Such datasets offer the potential to serve as the foundation for a systems‐approach to solve the dual public health problems of: (1) early detection of people who are at elevated risk for Alzheimer's disease, and (2) the development of interventions to delay onset of, or prevent, late‐life dementia. The symposium considered three interrelated components of a National Database for Longitudinal Studies on Healthy Aging as follows: (a) a registry of healthy aging adults; (b) refined computer‐based assessments for data gathering, including assessments of behavioral/memory changes associated with aging that are appropriate for broad use in nonexpert settings; and (c) high performance computing/supercomputer‐based approaches for health data modeling and mining.

BackgroundApolipoprotein E ɛ4 (APOE ɛ4) allele carrier status has been well established as a risk factor for developing Alzheimer's disease. However, the specific influence of APOE ɛ4 allele status on cognitive and functional rates of decline in mild cognitive impairment (MCI) is poorly understood. We examine the prospective association of APOE ɛ4 allele status on measures of cognitive and functional decline in subjects with amnestic MCI (aMCI).MethodsA total of 516 aMCI participants aged 55–90 years who received placebo or vitamin E from the Alzheimer's Disease Cooperative Study's MCI treatment trial were evaluated. During the 36‐month study period, neurocognitive and functional measures were collected. These measures were assessed over time for change and association with APOE ɛ4 status. Generalized Estimating Equations were performed to model each outcome measure over the study period.ResultsAPOE ɛ4 status had a significant impact on cognitive and functional decline on multiple measures; those who were APOE ɛ4 positive had significantly more rapid decline in performance on all cognitive and functional measures except Number Cancellation and Maze tracing (P < .05). The greatest decline was seen in global measures of cognition and function including the Clinical Diagnostic Rating scale, followed by the Mini‐Mental State Examination, Global Deterioration scale, and the Alzheimer's Disease Assessment Scale‐Cognitive Subscale.ConclusionsThese findings demonstrate that APOE ɛ4 genotype is predictive of increased general rates of decline with global measures of cognition and function most affected. With accelerated declines in common clinical trial primary efficacy measures, APOE ɛ4 status needs to be accounted for in treatment trials of MCI.