The night before the day after:connections between sleep problems and anxiety across the lifespan

Anxiety disorders are among the most frequently occurring mental disorders. Sleep problems are highly common as well. Poor sleep has been associated with anxiety in previous research. However, few studies have examined the association between sleep problems and anxiety across the lifespan, i.e. in young, middle aged, and older people. Furthermore, sleep deprivation and anxiety may be self-reinforcing since worrying may cause poor sleep, contributing to more anxiety and sleep problems. The aim of this thesis was to explore the prevalence of anxiety disorders and sleep problems, and the association between the two, covering large parts of the lifespan (adults aged 18-93 years and children aged 8-18 years). Of the total adult sample (n=75,669), 9.9% had a current diagnosis of any anxiety disorder and 15.1% reported current sleep problems. Whereas the prevalence of anxiety decreased with increasing age, the prevalence of sleep problems showed the opposite pattern. Furthermore, especially in men and young people poor sleep was related to more anxiety. In children and adolescents (n=8,504), anxiety symptoms and sleep problems were common as well and related to each other. In addition, in a study including 2,230 adolescents in which anxiety and sleep were repeatedly measured, poor sleep predicted anxiety over time at the level of the individual. Hence, the results of this thesis suggest that adolescents and young adults should receive special attention in intervention programs since treatment or prevention of sleep problems may decrease the risk of anxiety in this target group