Editor's note: Terra Ziporyn Snider is a medical writer, historian and former associate editor of the Journal of the American Medical Association. She is the executive director and co-founder of Start School Later, a nonprofit dedicated to increasing public awareness about the relationship between sleep and school hours. The opinions expressed in this commentary are solely those of the writer.
(CNN) -- The American Academy of Pediatrics' new recommendation to start middle and high schools no earlier than 8:30 a.m. is a turning point in the decades-old battle to start school later. Establishing adolescent sleep and school hours as public health issues -- and specifying an earliest acceptable bell time -- should energize communities to stop condemning another generation to chronic sleep deprivation.
The science supporting a return to later school start times is clear, and has been since the 1990s. As a science writer, I've read many compelling studies that show starting classes in the 7 a.m. hour -- not to mention sending sleep-deprived teenagers onto the streets as early as 5:30 a.m. -- is unhealthy, unsafe, and counterproductive. Raising three children who battled a 7:17 a.m. high school bell time erased any remaining doubts that they needed to start school later.
The root of the problem is that in puberty, a shift in circadian rhythms, or "body clocks," pushes optimal sleep time forward. Most teenagers simply can't fall asleep before 11 p.m. even if they're lying in bed for hours. When dawn rolls around, they haven't gotten close to the 8½ to 9½ hours of sleep their still-growing brains and bodies need.
The resulting sleep deprivation can produce mood swings, obesity, substance abuse, immune disorders, and depression. Teenagers suffering from chronic fatigue often can't pay attention in school and have difficulty concentrating and remembering. Their judgment can be impaired, and sleepy drivers can get in accidents.
"Almost all teenagers, as they reach puberty, become walking zombies because they are getting far too little sleep," says James B. Maas, a sleep expert at Cornell University.
Sleep deprivation in children is also what the Academy of Pediatrics calls "one of the most common -- and easily fixable -- public health issues in the U.S. today."
Turning science into policy that fixes it, however, is another matter. When my family first moved to Anne Arundel County, Maryland, in 2000, our school district had already approved a pilot to start one of its 12 high schools at 9 a.m. We were convinced that by the time my seventh-grader got into high school, the whole district would follow suit. That plan was axed at the last minute, and, since then, nothing has changed. That seventh-grader is now 26, and my baby, then in kindergarten, is a college sophomore.
Running schools from 7 a.m. until about 2 p.m. appears to be relatively new -- although record-keeping is poor -- despite common sentiment that "we've always done things this way." Schools seem to have shifted earlier primarily to save money on bus costs in the 1970s or 1980s, before sleep science had revealed much about adolescent sleep needs and patterns.
Reluctance to reverse a bad decision is understandable. Community life revolves around public school hours, and any change in schedule -- whether earlier or later -- inevitably stirs up powerful opposition.
Many people react to suggestions to change starting times with scorn, fear, or even vitriol. Adults have vested interests in the early-start, early-release school days, and those concerns often trump the best interests of kids. People are wary of how later hours will affect daycare, sports and other extracurricular activities, jobs, and even traffic patterns.
These fears help explain why most school systems resist starting the school day later, even when they want to do so. It doesn't help that sleep is an emotional and even a moral issue for many people, and, sadly, is often considered a luxury.
The good news is that we have solid evidence showing that fears about later bell times are groundless. Studies coming out of the University of Minnesota, Brown University, and the Children's National Medical Center provide evidence that running schools at developmentally appropriate hours not only improves health and academic performance but actually results in teenagers getting significantly more sleep. Community life adjusts to school schedules, not vice versa.
The true obstacles aren't sports or bus costs, but the fear of change and failure of imagination. We've found schools in 43 states that have worked out feasible, affordable ways to ensure later, healthier hours by putting health, safety, and learning first. Their solutions didn't require rocket science but, rather, a shift of priorities.