Department of Epidemiology, Erasmus Medical Centre, Rotterdam, The Netherlands.
J Psychiatr Res. 2013 Apr;47(4):479-85. doi: 10.1016/j.jpsychires.2012.12.008. Epub 2013 Jan 11.
Plasma amyloid β (Aβ) levels have been associated with an increased risk of Alzheimer's disease (AD). As depression is common before the onset of AD, a few clinical studies tested the cross-sectional association of Aβ levels with depression in elderly and showed incongruous findings. Hence, we tested the longitudinal association between Aβ levels and depressive symptoms in community-dwelling elderly. The study is embedded in a population-based cohort of 980 participants aged 60 years or older from the Rotterdam Study with Aβ levels. Participants were evaluated for depressive symptoms with the Centre for Epidemiological Studies-Depression scale at baseline and repeatedly over the mean follow-up of 11 years. We first performed cross-sectional analyses. Then, we tested the longitudinal association between Aβ levels and depressive symptoms after excluding participants with dementia during follow-up. In cross-sectional analyses, persons with high Aβ(1-40) levels had more clinically relevant depressive symptoms. However, this association was accounted for by persons with clinically relevant depressive symptoms who developed dementia within the next 11 years. In longitudinal analyses, persons with low levels of Aβ(1-40) and Aβ(1-42) without dementia had a higher risk of clinically relevant depressive symptoms during the follow-up. These findings suggest that the cross-sectional association between high plasma Aβ levels and clinically relevant depressive symptoms in the elderly is due to prodromal dementia. In contrast, the longitudinal association between low plasma Aβ levels and depressive symptoms could not be explained by dementia during follow-up suggesting that Aβ peptides may play a distinct role on depression etiology.
血浆淀粉样蛋白 β（Aβ）水平与阿尔茨海默病（AD）的风险增加有关。由于抑郁在 AD 发病前很常见，因此一些临床研究测试了 Aβ 水平与老年人群中抑郁的横断面关联，结果发现结果不一致。因此，我们测试了社区居住的老年人中 Aβ 水平与抑郁症状之间的纵向关联。该研究嵌入了一个基于人群的队列研究，其中包括来自鹿特丹研究的 980 名年龄在 60 岁或以上的参与者，这些参与者的 Aβ 水平可以进行评估。在基线和平均 11 年的随访期间，参与者使用流行病学研究抑郁量表评估抑郁症状。我们首先进行了横断面分析。然后，在排除随访期间发生痴呆的参与者后，测试了 Aβ 水平与抑郁症状之间的纵向关联。在横断面分析中，Aβ(1-40)水平较高的人有更多的临床相关抑郁症状。然而，这种关联是由在接下来的 11 年内发生痴呆的具有临床相关抑郁症状的人引起的。在纵向分析中，没有痴呆的 Aβ(1-40)和 Aβ(1-42)水平较低的人在随访期间发生临床相关抑郁症状的风险较高。这些发现表明，老年人中血浆 Aβ 水平较高与临床相关抑郁症状之间的横断面关联是由于前驱性痴呆。相比之下，在随访期间没有痴呆的情况下，血浆 Aβ 水平较低与抑郁症状之间的纵向关联不能用痴呆来解释，这表明 Aβ 肽可能在抑郁病因学中发挥独特的作用。
