Relationship of anxiety disorders, sleep quality, and functional impairment in a community sample

Background: Anxiety disorders and insomnia are each prevalent, impairing, and highly comorbid. However, little is known about whether specific types of sleep complaints are associated with specific anxiety disorders, and whether poor sleep has an additive effect on functional impairment in anxiety disorders. Method: Data from the German Health Survey (GHS; N = 4181: ages 18-65) were utilized to examine relationships among anxiety disorders, sleep quality (assessed by the Pittsburgh Sleep Quality Inventory; PSQI), and functional impairment (assessed by the Medical Outcomes Scale Short Form; SF-36; and past-month disability days due to physical and emotional problems, respectively). Results: Most anxiety disorders were significantly associated with global PSQI scores. Social phobia (AOR 3.95, 95% CI 1.73-9.04) and GAD (AOR 3.94, 95% CI 1.66-9.34) had the strongest relationships with global PSQI scores. Daytime dysfunction was the PSQI subscale most strongly associated with anxiety disorders, particularly GAD. Having a comorbid anxiety disorder and poor sleep was associated with significantly lower Mental Component Scores on the SF-36 than having an anxiety disorder alone (40.87 versus 43.87, p = .011) and with increased odds of one or more disability days due to emotional problems (AOR 2.72, 95% CI 1.35-5.48), even after controlling for sociodemographic factors and past-month mood and substance use disorders. Conclusions: Most anxiety disorders are moderately associated with reduced sleep quality. Individuals with anxiety disorders and poor sleep experience significantly worse mental health-related quality of life and increased disability relative to those with anxiety disorders alone. (C) 2009 Elsevier Ltd. All rights reserved.