As the school year approaches, Yale Medical Group sleep expert Meir Kryger, MD, has a message for parents: You must adjust your child’s sleep schedule, and that includes turning off cell phones and other electronic devices at least an hour before they go to sleep. Not doing so could open the door to poor school performance and health problems.\nDr. Kryger is a world-renowned expert on sleep, chief editor of “The Principles and Practice of Sleep Medicine,” the main textbook in sleep medicine, and author of the newly released e-book “The iGuide to Sleep.” He treats patients of all ages, and he recently discussed the importance of preparing for school.\nHow important is the summer-to-school schedule transition?\nVery important. Every parent knows that when school starts, kids who have been staying up late all summer hit a wall. This can be extremely jolting, and it can cause a period of great stress. In Canada, where I’m from, school starts at roughly 9 a.m., which is in tune with a child’s physiology. Here, I’ve had patients who get on the bus as early as 5:30 in the morning, and many are picked up at 7 a.m. So there is the potential for kids to become extremely sleep-deprived during the transition period.\nWhy don’t we change school start times?\nI suggested this to a school superintendent, and the story I got was if they changed the start time, it would mess up football schedules later in the day. That makes no sense. The purpose of school is education. Other answers are that schedules are complicated or early buses help them save money. But research shows when start times are changed, kids do better academically.\nBesides poor performance, what do we know about the effects of this lost sleep?\nWe don’t know all the answers, but we do know that for different ages, different amounts are optimum. We think that in young children, growth hormone is primarily produced during very deep sleep. The newest research shows that children who don’t sleep enough are more likely to be obese. There are certain hormones that make you stop eating, and certain hormones that make you eat, and they all go out of kilter when you lose sleep. Right now we’re seeing more children who have sleep apnea, sometimes due to enlarged tonsils, but often related to obesity. I’m talking about very young children—ages 3, 4, 5 and 6—who are massively obese.\nHow can you tell when a child has an actual sleep disorder?\nThe main symptoms we see are inability to focus, falling asleep in class, or even exhibiting hyperactive behavior. This is either because they are not getting enough sleep, or they have a disorder such as sleep apnea. Another problem is narcolepsy, which classically begins during the teen years. Doctors often miss these disorders, and it can take 10 to 20 years before narcolepsy is finally diagnosed. Teenagers who have an iron deficiency can also experience severe insomnia and daytime sleepiness, which improve once the iron deficiency is treated.\nCan bad habits turn into real disorders?\nThey can and they do. In older teenagers, we often see the circadian clock running late. They were going to sleep at 10:30 p.m., then all of a sudden they don’t get sleepy until 1, 2 or 3 in the morning. A big tip-off is that they are sleeping until 12:30 or 2 in the afternoon on weekends.\nSome of this is genetic, but it complicates matters is that kids are using electronic devices before bed—they are playing video games, surfing the internet, or texting on their smart phones. I’ve seen videos of children who look like they’re asleep, but they’re clutching their phones and they keep waking up to respond to incoming texts. The artificial light exposure before bed suppresses the release of melatonin, a sleep-promoting hormone. If you look at children between grades 6 and 12, you’ll see a progressive loss of sleep.\nHow do you know if your child needs help?\nChildren who are falling asleep at the wrong time in the wrong place probably need help. Parents also need to remember that their children will never come to them and say they have a sleep problem. Very often it’s the teacher who says the child is falling asleep in school or not focusing. Unfortunately, many of these children end up being treated for attention deficit disorder, which they may not even have.\nHow do you treat them?\nIf there is an underlying disorder, we can help. If the problem is obesity, we need to address that quickly. If a child diagnosed with sleep apnea has large tonsils and adenoids, they need to be taken out. If the child has sleep apnea caused by a malformation of the face, such as a small jaw, he can be treated with orthodontics. One of the first things we hear from parents, about six months after these operations and treatments is that the child had a growth spurt. Suddenly everything is working. The child is getting the right type and amount of sleep. Their grades improve.\nWhat if there is not an underlying disorder?\nIn those cases, it’s important to treat the parent and the child. If you’re a parent stuck with a school system that is not going to change its schedule, you just have to do the math, understanding that children need different amounts of sleep at different ages—seven to eight hours are simply not adequate. Say your child needs anywhere from 9 to 12 hours of sleep, depending on his age. He may have to go to bed at 8 o’clock in order to get up at 6, and there should be no electronics or caffeine beverages before bed. The parent is responsible for the well-being of the child, and sometimes the parent will have to be hardnosed and say, “I’m calling the shots.”\n To make an appointment with Yale Pulmonary & Critical Care Medicine, call 203-785-6760.