Adolescent Sleep Duration, Variability, and Peak Levels of Achievement and Mental Health.

To inform public health recommendations for adolescent sleep, the amounts of sleep associated with the highest levels of academic achievement and mental health were examined. The degree to which daily variability in sleep duration represents an underappreciated but functionally significant sleep behavior also was tested. A total of 421 adolescents (Mage  = 15.03 years) with Mexican-American backgrounds reported nightly sleep times for 2 weeks; approximately 80% repeated the same protocol 1 year later. Multilevel modeling indicated that the amount of sleep associated with the lowest levels of internalizing and externalizing symptoms was more than 1 hr greater than the amount associated with the highest levels of academic performance. Greater daily variability in sleep duration predicted greater symptomatology and mixed academic outcomes.