Lorenz Noah, Sander Christian, Ivanova Galina, Hegerl Ulrich
Department of Psychiatry and Psychotherapy, Faculty of Medicine, Leipzig University, Leipzig, Germany.
Research Centre of the German Depression Foundation, Leipzig, Germany.
JMIR Ment Health. 2020 Apr 23;7(4):e17071. doi: 10.2196/17071.
There is a strong link between sleep and major depression; however, the causal relationship remains unclear. In particular, it is unknown whether changes in depression core symptoms precede or follow changes in sleep, and whether a longer or shorter sleep duration is related to improvements of depression core symptoms.
The aim of this study was to investigate temporal associations between sleep and depression in patients suffering from major depressive disorder using an idiographic research approach.
Time-series data of daily sleep assessments (time in bed and total sleep time) and self-rated depression core symptoms for an average of 173 days per patient were analyzed in 22 patients diagnosed with recurrent major depressive disorder using a vector autoregression model. Granger causality tests were conducted to test for possible causality. Impulse response analysis and forecast error variance decomposition were performed to quantify the temporal mutual impact of sleep and depression.
Overall, 11 positive and 5 negative associations were identified between time in bed/total sleep time and depression core symptoms. Granger analysis showed that time in bed/total sleep time caused depression core symptoms in 9 associations, whereas this temporal order was reversed for the other 7 associations. Most of the variance (10%) concerning depression core symptoms could be explained by time in bed. Changes in sleep or depressive symptoms of 1 SD had the greatest impact on the other variable in the following 2 to 4 days.
Longer rather than shorter bedtimes were associated with more depression core symptoms. However, the temporal orders of the associations were heterogeneous.
睡眠与重度抑郁症之间存在紧密联系；然而，因果关系仍不明确。具体而言，尚不清楚抑郁核心症状的变化是先于还是后于睡眠变化，以及睡眠时间的长短与抑郁核心症状的改善是否相关。
本研究旨在采用个性化研究方法，调查重度抑郁症患者睡眠与抑郁之间的时间关联。
使用向量自回归模型，对22例诊断为复发性重度抑郁症的患者进行分析，这些患者平均每人有173天的每日睡眠评估（卧床时间和总睡眠时间）和自评抑郁核心症状的时间序列数据。进行格兰杰因果检验以测试可能的因果关系。进行脉冲响应分析和预测误差方差分解，以量化睡眠和抑郁的时间相互影响。
总体而言，卧床时间/总睡眠时间与抑郁核心症状之间确定了11个正相关和5个负相关。格兰杰分析表明，在9个关联中，卧床时间/总睡眠时间导致了抑郁核心症状，而在其他7个关联中，这种时间顺序则相反。关于抑郁核心症状的大部分方差（10%）可以由卧床时间来解释。睡眠或抑郁症状1个标准差的变化在接下来的2至4天对另一个变量的影响最大。
较长而非较短的卧床时间与更多的抑郁核心症状相关。然而，这些关联的时间顺序是异质的。
