Background

Trajectories of depressive symptoms over the lifespan vary between people, but it is unclear whether these differences exhibit distinct characteristics in brain structure and function.

Methods

In order to compare indices of white matter microstructure and cognitive characteristics of groups with different trajectories of depressive symptoms, we examined 774 participants of the Whitehall II Imaging Sub-study, who had completed the depressive subscale of the General Health Questionnaire up to nine times over 25 years. Twenty-seven years after the first examination, participants underwent magnetic resonance imaging to characterize white matter hyperintensities (WMH) and microstructure and completed neuropsychological tests to assess cognition. Twenty-nine years after the first examination, participants completed a further cognitive screening test.

Outcomes

Using K-means cluster modelling, we identified five trajectory groups of depressive symptoms: consistently low scorers (“low”; n = 505, 62·5%), a subgroup with an early peak in depression scores (“early”; n = 123, 15·9%), intermediate scorers (“middle”; n = 89, 11·5%), a late symptom subgroup with an increase in symptoms towards the end of the follow-up period (“late”; n = 29, 3·7%), and consistently high scorers (“high”; n = 28, 3·6%). The late, but not the consistently high scorers, showed higher mean diffusivity, larger volumes of WMH and impaired executive function. In addition, the late subgroup had higher Framingham Stroke Risk scores throughout the follow-up period, indicating a higher load of vascular risk factors.

Interpretation

Our findings suggest that tracking depressive symptoms in the community over time may be a useful tool to identify phenotypes that show different etiologies and cognitive and brain outcomes.

中文翻译：

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抑郁症状轨迹与血管风险、认知功能和不良大脑结果的关联：Whitehall II MRI 子研究。

背景

抑郁症状在一生中的轨迹因人而异，但尚不清楚这些差异是否在大脑结构和功能上表现出明显的特征。

方法

为了比较具有不同抑郁症状轨迹的群体的白质微观结构和认知特征指标，我们检查了 Whitehall II 成像子研究的 774 名参与者，他们完成了一般健康问卷的抑郁分量表多达 9 次25年。第一次检查 27 年后，参与者接受了磁共振成像以表征白质高信号 (WMH) 和微观结构，并完成了神经心理学测试以评估认知。第一次考试 29 年后，参与者完成了进一步的认知筛查测试。

结果

使用 K-means 聚类建模，我们确定了五个抑郁症状轨迹组：持续低分者（“低”；n = 505, 62·5%），一个在抑郁评分中出现早期峰值的亚组（“早期”；n = 123, 15·9%），中等评分者（“中等”；n = 89, 11·5%），晚期症状亚组，在随访期结束时症状增加（“晚期”；n = 29, 3·7%)，并且一直是高分者（“高”；n = 28, 3·6%）。晚期但并非始终如一的高分者表现出更高的平均扩散率、更大体积的 WMH 和受损的执行功能。此外，晚期亚组在整个随访期间的弗雷明汉卒中风险评分较高，表明血管危险因素的负荷较高。

解释

我们的研究结果表明，随着时间的推移跟踪社区中的抑郁症状可能是识别显示不同病因和认知和大脑结果的表型的有用工具。