PUB - Publikationen an der Universität Bielefeld

Both positive and negative experiences during childhood can shape the adult life. For example, previous studies have shown that maltreatment experiences in childhood are associated with a lower quality of sleep when grown up. The hyperarousal concept of insomnia is a widely accepted approach to explain difficulties with sleep initiation and maintenance. The model postulates that individuals suffering from insomnia have an increased baseline arousability on different levels. Therefore, somatic, cortical, and cognitive indicators of hyperarousal are differentiated. Nevertheless, the association between the hyperarousal model of insomnia and maltreatment experiences in childhood has rarely been examined. Taking child maltreatment into account can help to better understand the aftermaths of these events regarding sleep difficulties. This knowledge could help specifying and improving prevention and intervention programs regarding sleep problems or child welfare. Therefore, this dissertation explores the complex effects of child maltreatment focusing on the role of hyperarousal and sleep in adulthood. As part of the dissertation and to address this gap in research, a systematic review on sleeprelated hyperarousal in individuals with a history of child maltreatment was conducted. In the first manuscript, the state of research regarding this association were systematically reviewed, to (a) explore the applied methods to measure hyperarousal and (b) gather and compare the given information. The results of the systematic review were used to decide on how sleep-related hyperarousal is measured in the following manuscripts. In an experimental study, differences in hyperarousal in connection to objective and subjective sleep reactivity were examined in individuals with and without a history of child maltreatment. In stressful situations, the sympathetic nervous system is activated and the parasympathetic nervous system is deactivated. This is comparable to hyperarousal symptoms. Previous literature has shown that there are differences in the stress reaction of individuals with a history of child maltreatment compared to individuals without. Most studies report more blunted stress reactions, although there are also contradicting results. A stress paradigm was included into the study to explore whether individuals with and without a history of child maltreatment differ in their stress reaction. In the third manuscript another dimension of sleep-related hyperarousal was explored. Cognitive hyperarousal was operationalized as rumination tendency. Additionally, studies have demonstrated that sleep is also interlinked with romantic relationships which can improve sleep or serve as a risk factor for sleep difficulties depending on the perceived quality of the current romantic relationship. Up until now, research has not much focused on the role of maltreatment experiences in childhood in this context. Therefore, the role of romantic relationship satisfaction in the context of sleep and child maltreatment was examined. First relationships are built in early childhood with the parents or other caregivers. In this context, attachment plays an important role. Therefore, different attachment dimensions were included in the study as a third factor. Both experimental studies were designed as cross-sectional studies. The results of all three manuscripts contribute to the current state of research and the better understanding of the consequences of child maltreatment in adulthood. The systematic review has shown that individuals with a history of child maltreatment appear to have higher levels of sleep-related hyperarousal. The hyperarousal was operationalized on different levels. Some studies addressed cortical and cognitive hyperarousal, yet nocturnal activity and other somatic aspects of hyperarousal were mostly assessed. Nevertheless, the review pointed out that this topic is widely understudied and needs more attention. On a critical note, the studies were designed very heterogeneously which diminished the comparability between them. The second manuscript supported previous findings on decreased subjective sleep quality in adulthood. On the other hand, individuals with and without a history of child maltreatment did not differ regarding objective sleep quality or the stress reaction (autonomic arousal, neuroendocrine arousal). Finally, the third manuscript demonstrated two pathways to explain impaired sleep in adulthood after having experienced maltreatment in childhood. Both cognitive hyperarousal measured as rumination tendency and romantic relationship satisfaction significantly mediated the association between child maltreatment experiences and impaired sleep. Regarding attachment, individuals tended to be less comfortable with closeness to others. Comfort with closeness and romantic relationship satisfaction combined mediated adult sleep impairments. Further studies are needed to explore these associations more in detail. Intervention studies addressing sleep improvement should consider child maltreatment history as well as the enhancement of romantic relationship satisfaction.