COD E R E D

morbidly obese and diagnosed with obstructive sleep apnea were found to have lower scores on generalmemory, verbal memory, learning and vocabulary than those without obstructive sleep apnea (Rhodes etal., 1995). A laboratory study of children (mean ages 11.6 (intervention) and 12.3 (control)) with nomedical, learning, attentional, behavioral or psychiatric disorders found that the children randomlyassigned to the sleep-restricted group (5 hours in bed compared to 11 hours in bed) found significantimpairment in executive function including abstract thinking, verbal processing and creativity in the sleepdeprivedgroup compared to the controls with no difference in tasks requiring lower cognitive loads(Randazzo et al., 1998).Cross-sectional surveys of youth provide mixed evidence for a relationship between lifestylerelatedsleep loss and academic functioning. Among 3,120 Rhode Island high school students, those whoreport lower grades (Cs and below) sleep for approximately 25 fewer minutes and retire 40 minutes laterthan those who report higher grades (Wolfson A. R. & Carskadon, 1998). Among 1,200 high school andmiddle school students in Maryland, however, there was no consistent correlation between sleep time andchildren’s self reported GPA (Eliasson et al., 2002). Among 450 Ohio middle school students, there was asignificant linear effect for self-reported total sleep time and school achievement and total sleep time wasrelated to self-report of daytime sleepiness (Drake et al., 2003). A longitudinal study following 2,259students from 6 th to 8 th grade found positive correlations between self-reported hours of sleep on schoolnights and self-reported grades at all cross-sectional timepoints (Fredriksen et al., 2004). However,decreasing amounts of sleep from 6 th to 8 th grade did not predict lower grades, although it did predictincreased levels of depressive symptoms. The relationship between depression and sleep loss has beenreported by others (Roberts et al., 1997) and may explain some of the relationship between sleep loss andacademic performance.Limitations. The research on sleep related disorders resulting from sleep apnea syndrome isstrengthened by clinical diagnostic criteria and longitudinal designs with treatments but limited by issuesrelated to recruitment to sleep clinic studies or recruitment from sleep clinic populations and case-studydesigns. Studies of life-style related sleep loss are limited by their cross-sectional designs and self-reportmeasures.Implications. The clinical studies do support the relationship between obstructive sleep apnea or sleepdisorderedbreathing and executive function that may be related to academic performance. Furtherevidence is provided by the increase in attention and academic grades among children treated forobstructive sleep apnea through tonsillectomy or adenoidectomy. For life-style related sleep loss, there ismixed evidence that fewer minutes of sleep on school nights are related to grades, some evidence thatfewer minutes of sleep is related to daytime sleepiness, and some suggestion of a relationship betweensleep loss and depression.E-14