The German version of the Fear of Sleep Inventory - Short Form: A psychometric study

Fear of sleep in people with epilepsy

More than one third of people with epilepsy (PWE) report experiencing insomnia. This is highly concerning given that sleep loss both triggers and exacerbates seizures. It is therefore paramount that we understand the underlying mechanisms of insomnia in PWE. Nevertheless, research in this area remains limited, with little understanding of the emerging or maintaining factors of insomnia in PWE. Therefore, the current study sought to explore fear of sleep as a novel explanation for the increased rate of insomnia in PWE, and whether fear of sleep was related to post-seizure trauma. We recruited 184 PWE and 197 healthy controls via social media and collected data using a series of online questionnaires. We found that fear of sleep did not significantly differ between the epilepsy and control group. In the epilepsy group, fear of sleep seemed to be largely driven by trauma, especially post-seizure trauma but also non-seizure related trauma, along with anxiety and higher seizure frequency. Fear of sleep in the control group was also largely driven by trauma, but also anxiety and depression. Finally, we found more severe and prevalent insomnia in PWE relative to controls, and in both groups, fear of sleep was the most significant contributor to insomnia. Our novel findings carry important clinical implications. First, they point to the central role of trauma in fear of sleep not only in PWE but also in the general population. Our findings also indicate that fear of sleep is an important maintaining factor of insomnia. Ultimately, these results suggest that all individuals with insomnia may benefit from insomnia interventions targeted at trauma, depression, anxiety, and fear of sleep. PWE are likely to benefit from additional treatment components for seizure-related trauma and seizure management. To better understand the reliability and generalisability of our novel findings, future research should further assess fear of sleep and its role in maintaining insomnia in the epilepsy population.

Symptom dynamics among nightmare sufferers: An intensive longitudinal study

Nightmares are considerably prevalent in the general population and are known to be closely associated with a variety of mental disorders. However, not much is known about the immediate antecedents and consequences of nightmares. Therefore, we used intensive longitudinal assessments to investigate the night-to-night within-person associations between nightmares on the one hand and fear of sleep, somatic as well as cognitive pre-sleep arousal, and sleep quality on the other hand. Young women with regular nightmares (n = 16) maintained a sleep diary for around 30 days; upon awaking, the participants reported on nightmares and sleep quality during the past night as well as the pre-sleep levels of arousal and fear of sleep (which resulted in 461 observations). Participants also wore an actigraph, which provided objective sleep parameters. Multilevel modeling showed that higher levels of fear of sleep and lower subjective sleep quality were significantly associated with higher levels of nightmare distress. Furthermore, we found individual differences in the strength of these associations, which implies that factors proximate to nightmares may vary across individuals. Pre-sleep arousal, however, did not show expected within-person associations with nightmares or fear of sleep. These findings highlight the crucial role of fear of sleep in the etiology of nightmares and sleep disturbances, while pointing to the importance of pursuing individual, personalised models that explain heterogeneity in the process of triggering nightmares.

Fear of sleep and trauma-induced insomnia: A review and conceptual model

Trauma-induced insomnia is a symptom of posttraumatic stress disorder (PTSD), and is reported to be particularly distressing and often persists even after remission of the core symptoms of PTSD. Recently, it has been suggested that fear of sleep plays an important role in the development and maintenance of trauma-induced insomnia. The aim of this review is to propose a conceptual model of fear of sleep as a maintaining factor of trauma-induced insomnia. After a brief overview of the role of sleep in PTSD, the concept of fear of sleep is introduced. Theoretical considerations and empirical findings on the role of fear of sleep for trauma-induced insomnia in the context of PTSD are summarized and integrated. Specifically, links between PTSD symptoms and fear of sleep are presented, as well as possible consequences of fear of sleep leading to trauma-induced insomnia. Finally, we highlight methodological issues, identify areas for future research, and discuss potential clinical implications.

Pre-Sleep Arousal and Fear of Sleep in Trauma-Related Sleep Disturbances: A Cluster-Analytic Approach

Background

Trauma-related sleep disturbances constitute critical symptoms of posttraumatic stress disorder (PTSD), but sleep symptoms often reside even after successful trauma-focused psychotherapy. Therefore, currently unattended factors - like fear of sleep (FoS) - might play a crucial role in the development and maintenance of residual sleep disturbances. However, it is unclear whether trauma-exposed individuals exhibit different symptomatic profiles of sleep disturbances that could inform individualized therapeutic approaches and eventually enhance treatment efficacy.

Method

In a large online study, a two-step cluster analysis and a hierarchical cluster analysis using Ward's method were performed to explore subgroups among trauma-exposed individuals (N = 471) in terms of FoS, different aspects of trauma-related sleep disturbances (e.g., insomnia symptoms, nightmares, arousal), and PTSD symptoms. These variables were compared between resulting clusters using ANOVAs and Scheffé's post-hoc tests.

Results

The hierarchical cluster analysis supported 3- and 4-cluster solutions. The 3-cluster solution consisted of one "healthy" (n = 199), one "subclinical" (n = 223), and one "clinical" (n = 49) cluster, with overall low, medium, and high symptomatology on all used variables. In the 4-cluster solution, the clinical cluster was further divided into two subgroups (n = 38, n = 11), where one cluster was specifically characterized by elevated somatic pre-sleep arousal and high levels of FoS.

Conclusions

A subgroup of trauma-exposed individuals with PTSD and sleep disturbances suffers from increased pre-sleep arousal and FoS, which has been suggested as one possible explanation for residual sleep disturbances. In these patients, FoS might be a relevant treatment target.