The Scientific Case for Starting High School Later

摘要: If your community is debating later start times for high school, you probably have the hormone melatonin to thank. Changes in brain during adolescence alter teens' circadian rhythm, their internal body clock. Circadian rhythm controlled by suprachiasmatic brain's hypothalamus that responds signals from optic nerve, which senses light and dark (National Sleep Foundation 2014). In morning, triggers telling SCN it's time wake, signaling other parts of raise temperature delay release melatonin, produced when eyes signal dark. Melatonin levels rise evening--increasing sleepiness--and stay elevated throughout night, promoting sleep. A problem many teens at night than most children adults, causing them go bed--and want get up--at times. "Most preteens need 10 12 hours sleep each but this begins change as rhythms resetting, number they reduced," says Mary Lou Gavin, senior medical editor KidsHealth.org president Delaware Chapter American Academy Pediatrics (AAP). "While only 8.5 9.5 sleep, don't really feel sleepy until night." Unfortunately, some 68% school students less eight on an average according latest annual Youth Risk Behavioral Surveillance study (Kann et al. Maida Chen, who directs Seattle Children's Hospital's pediatric disorder center, 90% teenage patients a common problem: "Insufficient sleep." She leading cause early (Reddy The AAP (2014) recommends schools starting classes least 8:30 a.m. align with "the biological adolescents, whose sleep-wake cycles begin shift up two puberty." "Adolescents enough often suffer physical mental health problems," recommendation announced just before 2014 year started. "But getting can be hard natural make it difficult fall asleep 11 p.m.--and face first-period class 7:30 or earlier next day." Only about 15% U.S. later, says. "Chronic loss adolescents one common--and easily fixable--public issues today," Judith Owens, lead author director medicine National Medical Center Washington, D.C. reduced risk being overweight suffering depression, are likely involved automobile accidents, better grades, higher standardized test scores, overall quality life. …