Department of Neuroscience, University of Sheffield , Sheffield , UK.
Institute of Clinical Medicine, Neurology, University of Eastern Finland , Kuopio , Finland.
Postgrad Med. 2019 Sep;131(7):533-538. doi: 10.1080/00325481.2019.1663127. Epub 2019 Sep 10.
: Depression in patients with mild cognitive impairment (MCI) and dementia of the Alzheimer's type (AD) is associated with worse prognosis. Indeed, depressed MCI patients have worse cognitive performance and greater loss of gray-matter volume in several brain areas. To date, knowledge of the factors that can mitigate this detrimental effect is still limited. The aim of the present study was to understand in what way cognitive reserve/brain reserve and depression interact and are linked to regional atrophy in early stage AD. : Depression was evaluated with the Patient Health Questionnaire-9 in 90 patients with early AD, and a cutoff of ≥ 5 was used to separate depressed ( = 44) from non-depressed ( = 46) patients. Each group was further stratified into high/low cognitive reserve/brain reserve. Cognitive reserve was calculated using years of education as proxy, while normalized parenchymal volumes were used to estimate brain reserve. Voxel-based morphometry was carried out to extract and analyze gray-matter maps. 2 × 2 s were run to test the effect of the reserve-by-depression interaction on gray matter. Age and hippocampal ratio were used as covariates. Composite indices of major cognitive domains were also analyzed with comparable models. : No reserve-by-depression interaction was found in the analytical models of gray matter. Depression was associated with less gray matter volume in the cerebellum and parahippocampal gyrus. The brain reserve-by-depression interaction was a significant predictor of executive functioning. Among those with high brain reserve, depressed patients had poorer executive skills. No significant results were found in association with cognitive reserve. : These findings suggest that brain reserve may modulate the association between neurodegeneration and depression in patients with MCI and dementia of the AD type, influencing in particular executive functioning.
轻度认知障碍（MCI）和阿尔茨海默病（AD）患者的抑郁与预后较差有关。事实上，抑郁的 MCI 患者认知表现更差，大脑多个区域的灰质体积损失更大。迄今为止，对于可以减轻这种不利影响的因素的了解仍然有限。本研究的目的是了解认知储备/大脑储备和抑郁如何相互作用，并与早期 AD 的区域萎缩相关。
在 90 例早期 AD 患者中使用患者健康问卷-9 评估抑郁，使用≥5 作为分界值将抑郁患者（n=44）与非抑郁患者（n=46）分开。每组进一步分为高/低认知储备/大脑储备。使用受教育年限作为认知储备的替代指标，而正常化脑实质体积用于估计大脑储备。进行基于体素的形态测量学以提取和分析灰质图谱。进行 2×2 检验以检验储备与抑郁相互作用对灰质的影响。使用年龄和海马比率作为协变量。使用类似的模型分析主要认知领域的综合指数。
在灰质的分析模型中未发现储备与抑郁的相互作用。抑郁与小脑和海马旁回灰质体积减少有关。大脑储备与抑郁的相互作用是执行功能的重要预测因子。在大脑储备高的患者中，抑郁患者的执行功能较差。与认知储备没有显著关联。
这些发现表明，大脑储备可能调节 MCI 和 AD 型痴呆患者神经退行性变与抑郁之间的关联，特别是影响执行功能。
