Associations of sleep duration on school nights with self-rated health, overweight, and depression symptoms in adolescents: problems and possible solutions.

OBJECTIVE: To investigate associations between sleep duration and health-related measures, and factors associated with short sleep, in adolescents in an East Asian society with strong emphasis on academic achievement.

METHODS: Adolescents aged 13-19 years (n = 2346) from eight schools in Singapore (five local, three international) took part in a cross-sectional survey of sleep habits, school life, and health. Self-rated health, overweight (International Obesity Task Force Criteria), and depression symptoms were compared in adolescents with short (<7 h), moderately short (7 to <8 h), or an appropriate amount of sleep (8-10 h) on school nights.

RESULTS: Short sleep on school nights was associated with poorer self-rated health, increased odds of being overweight (adjusted odds ratio [ORadj ] = 2.56, 95% confidence interval = 1.39-4.70), and increased odds of feeling depression symptoms (sadness, irritability, worthlessness, low motivation, difficulty concentrating, anhedonia, anxiety, and thoughts of self-harm/suicide) compared with an appropriate sleep duration (ORadj  = 2.10-4.33, p < 0.05 for each symptom). Barriers to healthy sleep included later preferred sleep timing (a relative indicator of later chronotype), lower parental supervision of bedtime, longer study time, early school start time, and longer travel time. Students at local schools were less likely to have a parent-set bedtime, and spent more time on homework/studying. Later bedtime in local schools attenuated the benefit of later school start time on nocturnal sleep duration.

CONCLUSIONS: Short sleep may contribute to poorer adolescent health and well-being. Strategies for improving sleep in hard-driving East Asian societies should take into account sociocultural factors that may impede removal of barriers to healthy sleep.