"Vita-Salute" San Raffaele University, Faculty of Psychology, Milan, Italy; IRCCS San Raffaele Scientific Institute, Department of Clinical Neurosciences, Neurology - Sleep Disorders Center, Milan, Italy.
"Vita-Salute" San Raffaele University, Faculty of Psychology, Milan, Italy; IRCCS San Raffaele Scientific Institute, Department of Clinical Neurosciences, Neurology - Sleep Disorders Center, Milan, Italy.
Sleep Med. 2018 May;45:55-61. doi: 10.1016/j.sleep.2017.10.002. Epub 2017 Oct 24.
Repetitive thought is a hallmark of several psychopathological conditions and in particular a perpetuating and maintaining factor in Insomnia Disorder. Accordingly, one of the primary complaints reported by Insomnia patients is the inability to shut-off or control thoughts. Worry and rumination are the two best-known styles of repetitive thought leading to sleep disturbances. The aim of this study was to investigate the relationship of these two cognitive processes on nocturnal sleep indices objectively recorded by polysomnography.
27 Insomnia patients and 20 healthy controls matched for sex and age were recruited and completed a comprehensive assessment aimed to evaluate sleep quality, excessive daytime sleepiness, insomnia severity, worry, rumination, depressive and anxious symptomatology, and the ability to produce reasonable cognitive estimates. Sleep diaries indices and polysomnographic recordings were evaluated.
Insomnia patients showed increased levels of worry and rumination in comparison to controls. Our polysomnographic study revealed that these two different types of repetitive thoughts were significantly associated with objective sleep variables. In particular, heightened worry levels were related to an augmented wake after sleep onset and diminished total sleep time, sleep efficiency and percentage of REM sleep, whereas rumination was associated with an increase of sleep latency and a decrement of sleep efficiency. However, after controlling for anxiety and depressive symptoms only worry maintained a significant relationship with polysomnographic variables. Remarkably, repetitive thoughts did not correlate with microstructural REM sleep features and quantitative EEG analysis.
Our study indicates the existence of a significant relationship between daytime levels of repetitive thought and sleep, thus corroborating the hypothesis of an interplay between cognitive and nocturnal electrophysiological activity in insomniacs.
重复思维是几种精神病理学状况的标志，尤其是在失眠症中是一种持续和维持的因素。因此，失眠症患者报告的主要症状之一是无法关闭或控制思维。担忧和反刍是导致睡眠障碍的两种最著名的重复思维方式。本研究旨在调查这两种认知过程与多导睡眠图客观记录的夜间睡眠指标之间的关系。
招募了 27 名失眠症患者和 20 名性别和年龄匹配的健康对照组，并完成了一项全面评估，旨在评估睡眠质量、日间嗜睡、失眠严重程度、担忧、反刍、抑郁和焦虑症状以及产生合理认知估计的能力。评估了睡眠日记指标和多导睡眠图记录。
与对照组相比，失眠症患者的担忧和反刍水平增加。我们的多导睡眠图研究表明，这两种不同类型的重复思维与客观睡眠变量显著相关。具体而言，较高的担忧水平与睡眠后觉醒增加和总睡眠时间、睡眠效率和 REM 睡眠百分比减少有关，而反刍则与睡眠潜伏期增加和睡眠效率降低有关。然而，在控制焦虑和抑郁症状后，只有担忧与多导睡眠图变量保持显著关系。值得注意的是，重复思维与 REM 睡眠的微观结构特征和定量 EEG 分析没有相关性。
我们的研究表明，日间重复思维水平与睡眠之间存在显著关系，从而支持认知与失眠症患者夜间电生理活动相互作用的假设。
