Poor sleep and neurocognitive function in early adolescence.

BACKGROUND Evidence regarding the associations between sleep duration and quality, and neurocognitive function in adolescents remains scanty. This study examined the associations in early adolescence between: sleep duration; efficiency; fragmentation; wake-after-sleep-onset (WASO); catch-up sleep; intelligence; memory; and executive function, including attention. METHODS This study included 354 girls and boys with a mean age 12.3 years (SD = 0.5) from a birth cohort born in 1998. Sleep was measured with accelerometers for an average of eight nights. Cognitive function was evaluated with subtests from the Wechsler Intelligence Scale for Children-III (WISC-III), the Developmental Neuropsychological Assessment 2 (NEPSY-2), the Wisconsin Card Sorting Task (WCST), Conners' Continuous Performance Task (CPT), and the Trail Making Test (TMT). RESULTS In girls, a higher WASO and fragmentation index were associated with poorer executive functioning (higher number of perseverative errors in the WCST), and longer catch-up sleep was associated with longer reaction times and better performance in one verbal intelligence test (Similarities subtest of the WISC-III). In boys, shorter sleep duration, lower efficiency, higher WASO, higher sleep fragmentation and shorter catch-up sleep were associated with lower executive functioning (more commission errors, shorter reaction times, and had lower D Prime scores in CPT). CONCLUSIONS In adolescent girls, poorer sleep quality was only weakly associated with poorer executive functioning, while in boys, poorer sleep quantity and quality were associated with an inattentive pattern of executive functioning. The amount of catch-up sleep during weekends showed mixed patterns in relation to neurocognitive function.