The exploratory power of sleep effort, dysfunctional beliefs, and arousal for insomnia severity and PSG determined sleep

Abstract

Introduction Differences between subjective sleep perception and sleep determined by polysomnography (PSG) are prevalent in patients with primary insomnia, indicating that the two measures are partially independent. Objectives To identify individualized treatment strategies, it is important to understand the potentially different mechanisms influencing subjective and PSG determined sleep. Aims The aim of this study was to investigate to which extent sleep effort, dysfunctional beliefs and attitudes about sleep, and pre-sleep arousal are associated with subjective insomnia severity and PSG- determined sleep. Methods 47 patients with primary insomnia and 52 good sleeper controls underwent two nights of PSG and filled in the Glasgow Sleep Effort Scale, the Dysfunctional Beliefs and Attitudes about Sleep Scale, the Pre-Sleep Arousal Scale and the Insomnia Severity Index. Regression analyses adjusted for age, gender, depressive symptoms, and group status were conducted to investigate the impact of the three predictors on subjective insomnia severity and PSG- determined total sleep time. Results Subjective insomnia severity was positively associated with sleep effort. PSG determined total sleep time was negatively associated with somatic pre-sleep arousal and dysfunctional beliefs and attitudes about sleep. Conclusions The pattern of results suggests that subjective insomnia severity and PSG determined total sleep time are driven by different mechanisms. Being associated with subjective sleep disturbance, which defines the diagnosis of insomnia, the reduction of sleep effort appears to be an important therapeutic target for all patients. Somatic pre-sleep arousal and dysfunctional beliefscould be a target for patients who suffer from markedly reduced PSG determined total sleep time.