PUB - Publikationen an der Universität Bielefeld

Sleep problems are common among university students and are associated with lower grades, longer study duration, and psychological problems. Insomnia symptoms are linked with stress, poor quality of life, more anxiety, and more depressive symptoms, but also with increased pain symptoms. Approximately 18% of German universities students experience insomnia symptoms. A widely used model for insomnia is the cognitive model of Harvey: Negative cognitive activity leads to increased arousal, which is associated with a misperception of sleep and a cognitive bias regarding sleep. Consequences of poor sleep quality and the role of sleep are overestimated. At the end of the model, there are actual impairments in nighttime sleep quality as well as daytime functioning; a cycle is created that perpetuates sleep disturbance.
In line with this model, in the first study (Study I), negatively colored cognitive activity as a potential trigger of poor sleep quality was influenced using a positive psychology exercise. The second and third studies focused primarily on daytime impairments-both psychological and somatic symptoms (Study II), as well as concentration and memory (Study III). The second study examined the influence of sleep parameters, such as sleep onset latency and sleep duration, on somatic complaints and reviewed the relationship between anxiety, depressiveness, sleep quality, and somatoform complaints. In addition, this was a cross-sectional study of the prevalence of self-reported psychological distress at a German university. In the third study, a cognitive-behavioral intervention with hypnotherapeutic and imaginative elements was conducted for students with poor sleep quality. Its influence on sleep quality and on subjective and objective neurocognitive performance was examined.
A total of 134 students were included in the intervention studies and 2443 students in the cross-sectional study in this dissertation. Subjective sleep quality improved with positive thoughts before bedtime, analogous to Harvey's model. Furthermore, there was a correlation between poor sleep quality, increased somatoform symptoms as well as depressiveness and an indirect influence on anxiety in students, which is why the consequences of poor sleep quality according to Harvey's model were also confirmed in this dissertation. In the third study, an improvement in objective neurocognitive performance was observed in the intervention group, but also in the waiting list control group. Here, an improvement in sleep quality in both groups does not allow a clear conclusion. However, the subjective limitations of cognitive performance improved significantly in the intervention group.
This dissertation contributes to a better understanding of mental health in university students - with a focus on sleep quality. It also expands the set of trainings for students with sleep problems to help with poor sleep quality, as well as with sleep onset and sleep maintenance problems, and to mitigate any consequences of poor sleep quality. For the first time, the direct influence of anxiety, depression, and poor sleep quality on increased somatoform symptoms was shown in a statistical model (Study II). The improvement of sleep quality by an exercise from positive psychology was shown in the population of university students (Study I) - this result is consistent with recent studies. The interventional improvement of neurocognitive performance, however, could not be achieved, as in other studies on older subjects (Study III).