Associations of executive function with sleepiness and sleep duration in adolescents.

BACKGROUND Sleep deprivation and sleepiness are associated with poorer school performance, impaired neurobehavioral functioning, and behavioral problems. OBJECTIVE To determine if adolescents with high levels of sleepiness or short sleep duration have impaired executive functioning. METHODS Ours was a cross-sectional analysis of data from 236 healthy adolescents in a community-based cohort study. Sleepiness was measured by using a modified version of the Epworth Sleepiness Scale. Participants underwent 5- to 7-day wrist actigraphy at home before overnight polysomnography. Exposure variables were excessive sleepiness (Epworth Sleepiness Scale > or = 11) and weekday mean sleep duration. The main outcome measures were the global executive composite scale from the Behavior Rating Inventory of Executive Function and the tower test-total achievement score from the Delis-Kaplan Executive Functioning System. RESULTS Participants (N = 236) were 13.7 +/- 0.8 years of age, and 52.1% were boys. Mean weekday sleep duration was 7.70 +/- 1.03 hours; 11% slept <6.5 hours on average on weekdays, and 26% reported excessive sleepiness. In unadjusted analyses, sleepy adolescents had poorer executive functioning on the Behavior Rating Inventory of Executive Function global executive composite scale and the Delis-Kaplan Executive Functioning System tower test-total achievement. Analyses adjusted for potential confounders resulted in a modest attenuation of the association with the Behavior Rating Inventory of Executive Function and a larger attenuation for the Delis-Kaplan Executive Functioning System. Caregiver education modified the association between sleepiness and the Behavior Rating Inventory of Executive Function outcomes. Among sleepy adolescents, those with less-educated caregivers had greater impairment on the Behavior Rating Inventory of Executive Function global executive composite scale. Sleep duration was not significantly associated with executive functioning outcomes. CONCLUSIONS Decrements in selected executive function scales are associated with subjective sleepiness, but not sleep duration, in adolescents. The association between sleepiness and executive functioning is strongest among adolescents with primary caregivers who have lower levels of education, suggesting an increased susceptibility. Pediatricians and public health officials should consider sleepiness as a potentially important contributor to adolescent functioning.