Division of Geriatric Psychiatry, Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA.
Age Ageing. 2011 Nov;40(6):684-9. doi: 10.1093/ageing/afr101. Epub 2011 Sep 2.
studies of cognitive ageing at the group level suggest that age is associated with cognitive decline; however, there may be individual differences such that not all older adults will experience cognitive decline.
to evaluate patterns of cognitive decline in a cohort of older adults initially free of dementia.
DESIGN, SETTING AND SUBJECTS: elderly Catholic clergy members participating in the Religious Orders Study were followed for up to 15 years. Cognitive performance was assessed annually.
performance on a composite global measure of cognition was analysed using random effects models for baseline performance and change over time. A profile mixture component was used to identify subgroups with different cognitive trajectories over the study period.
from a sample of 1,049 participants (mean age 75 years), three subgroups were identified based on the distribution of baseline performance and change over time. The majority (65%) of participants belonged to a slow decline class that did not experience substantial cognitive decline over the observation period [-0.04 baseline total sample standard deviation (SD) units/year]. About 27% experienced moderate decline (-0.19 SD/year), and 8% belonged to a class experiencing rapid decline (-0.57 SD/year). A subsample analysis revealed that when substantial cognitive decline does occur, the magnitude and rate of decline is correlated with neuropathological processes.
in this sample, the most common pattern of cognitive decline is extremely slow, perceptible on a time scale measured by decades, not years. While in need of cross validation, these findings suggest that cognitive changes associated with ageing may be minimal and emphasise the importance of understanding the full range of age-related pathologies that may diminish brain function.
群体水平的认知老化研究表明，年龄与认知能力下降相关；然而，个体之间可能存在差异，并非所有老年人都会经历认知能力下降。
评估一组最初无痴呆的老年人的认知下降模式。
设计、设置和受试者：参加宗教秩序研究的老年天主教神职人员作为队列进行了长达 15 年的随访。每年评估认知表现。
使用随机效应模型分析基线表现和随时间变化的综合全球认知表现。使用混合成分模型来识别研究期间具有不同认知轨迹的亚组。
在 1049 名参与者（平均年龄 75 岁）的样本中，根据基线表现和随时间变化的分布确定了三个亚组。大多数（65%）参与者属于缓慢下降组，在观察期间没有经历大量认知能力下降[-0.04 基线总样本标准差（SD）单位/年]。约 27%的参与者经历了中度下降（-0.19 SD/年），8%的参与者属于快速下降组（-0.57 SD/年）。子样本分析表明，当发生实质性认知下降时，下降的幅度和速度与神经病理学过程相关。
在该样本中，最常见的认知下降模式是极其缓慢的，在几十年的时间尺度上可以察觉，而不是几年。虽然需要进一步验证，但这些发现表明，与衰老相关的认知变化可能很小，并强调了理解可能降低大脑功能的全范围与年龄相关的病理学的重要性。
