Poor academic performance may not be the result of lack of effort. A new study, reported in Pediatrics (June 2005), found that sleep deprivation is a factor.
For the study, 60 high school seniors kept sleep/awake diaries during the summer and at various times during the school year. A group of 19 students were also exposed to a bright light each morning to readjust their biological clocks. The researchers also evaluated the students using a computer test to measure reaction times, and a paper-and-pencil exam to test mood and cognitive performance.
During August, when school was closed, the participants averaged 8.7 hours of sleep a night. After school started, that number dropped to an average of 7 hours a night on weekdays. During the summer weekends, the participants' sleep patterns were similar to summer weekdays. Once school was in session, however, the participants slept about 30 minutes more on weekends than on summer weekendsabout 9 to 9.5 hours.
Testing skills were better in the afternoon, compared with early morning. In the reaction test, students completed the tests about 20 seconds faster in the afternoon than they had in the morning.
One study linked multiple pregnancies to an increased risk of developing atrial fibrillation later in life, and another investigated the association between premature delivery and cardiovascular disease.
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