title: Sleep disturbances and mental strain in university students: results from an online survey in Luxembourg and Germany.
abstract: OBJECTIVE
  This study examined the prevalence of sleep disturbances and mental strain in students from two European countries, Luxembourg and Germany.
  
  
  METHODS
  A total of 2831 students took part in an online survey, with 2777 students from Germany and 184 students from Luxembourg. Sleep disturbances were assessed with the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale, and aspects of mental strain using the Patient Health Questionnaire, the Social-Interactive-Anxiety Scale, the self-efficacy questionnaire and the test anxiety questionnaire. In addition, we also assessed students' chronotypes.
  
  
  RESULTS
  Across the whole sample mean scores on the sleep questionnaires were above the cut-off for clinically relevant sleep problems, indicating an increased prevalence of sleep disturbances in students from both countries. Sleep quality was impaired in 42.8%, and 17.9% showed clinically relevant scores. Overall 25.5% reported elevated depression and 13.3% social phobia symptoms, while 45% indicated elevated stress levels. Sleep quality, daytime sleepiness, chronotype, depression scores, stress levels, test anxiety, and self-efficacy differed significantly between men and women, but there were no differences between countries.
  
  
  CONCLUSIONS
  Sleep disturbances and mental strain in students are common, with the current results replicating previous findings. Students from Luxembourg and Germany are affected equally.
authors.affiliation: Department of Psychology and Sports, Faculty for Psychology and Sports, Bielefeld University, POP 10 01 31, 33501 Bielefeld, Germany.
authors.forename: Angelika A
authors.initials: AA
authors.lastname: Schlarb
authors.affiliation: Department of Psychology and Sports, Faculty for Psychology and Sports, Bielefeld University, POP 10 01 31, 33501 Bielefeld, Germany.
authors.forename: Merle
authors.initials: M
authors.lastname: Claßen
authors.affiliation: Department of Psychology, Faculty of Science, University of Tübingen, Schleichstrasse 4, 72076 Tübingen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Grünwald
authors.affiliation: Research Unit INSIDE, Institute for Health and Behaviour, University of Luxembourg, 2, Avenue de l'Université, L-4365 Esch-Sur-Alzette, Luxembourg.
authors.forename: Claus
authors.initials: C
authors.lastname: Vögele
keywords: Depression; European students; Mental health; Sleep; Stress