Too tired for school? The effects of insomnia on absenteeism in adolescence.

OBJECTIVES: Sleep has important consequences for a person's daytime functioning. Numerous studies have shown that insomnia predicts work absenteeism and work disability in adults, but only a few studies have examined this association in adolescents. This study aims to explore whether symptoms of insomnia in adolescents predict school absenteeism 1 year later, over and above known psychological risk factors for absenteeism. DESIGN: The study used a longitudinal design with 2 measurement points over 1 year. SETTING: The students completed questionnaires during school hours at baseline and again at follow-up. PARTICIPANTS: Students in the 10th to 12th grades in a Swedish upper secondary school were followed prospectively for 1 year (age, 16-20 years; N = 353; 48.1% girls). MEASUREMENTS AND RESULTS: We used logistic regression analyses, controlling for the known effects of psychological factors, and arrived at a model elucidating the role of insomnia. That is, besides symptoms of insomnia, the model included previous absenteeism, alcohol intoxication, school-related social phobia, social anxiety, depressive symptoms, somatic symptoms, and bully victimization. Symptoms of insomnia predicted school absenteeism 1 year later, over and above known risk factors for absenteeism. Adolescents reporting severe symptoms of insomnia were almost 3 times more likely than adolescents reporting no or low symptoms to report problematic absenteeism 1 year later. We did not find any gender difference. CONCLUSIONS: Our findings underscore the importance of sleep problems on adolescents' daytime functioning as measured by school absenteeism. Therefore, sleep may be an important target for preventive interventions with adolescents.