RESUMO
OBJECTIVES: The first aim of this study was to assess the prevalence of sleep deficit in a large sample of adolescents. Second, the study aimed to assess whether short sleep duration in the sample was associated with emotional and behavioral problems. Lastly, the study aimed to investigate the association between daily stressors--bedtime activities and sleep duration. DESIGN: Cross-sectional survey. SETTING: The questionnaires were completed during school hours in 17 municipal junior high schools in Sweden. PARTICIPANTS: A total of 2767 adolescents aged 12 to 16 years, 48% girls. MEASUREMENTS AND RESULTS: Sleep measures included total sleep time (TST) for schooldays and weekends, obtained as combined measures of self-reported bed-time, wake-time, and sleep onset latency. We used the new National Sleep Foundation's guidelines to operationalize sleep duration. Overall 12% of younger adolescents (age 12-13 years) and 18% of older adolescents (14-16 years) slept less than recommended (TST < 7 hours). Adolescents reporting nonrecommended TST also reported more behavioral (ie, norm-breaking behaviors) and emotional problems (ie, depression, anxiety, and anger), with effects in the small-medium range. Finally, adolescents reporting bedtime arousal and use of information and communication technology in bed were more likely to report TST < 7 hours. Stress at home (for younger adolescents) and stress of school performance (for older adolescents) were also associated with TST less than 7 hours. CONCLUSIONS: The new National Sleep Foundation's recommendations were informative in this context. Future sleep interventions need to target barriers to good sleep practices, such as use of information and communication technology, stress, and worry that may contribute to arousal at bedtime.