DEAR MAYO CLINIC: My 12-year-old daughter goes to bed each night around 10 p.m., but usually can't fall asleep until 1 or 2 in the morning. Is this normal for a "tween," or should I talk to her doctor? What are some things that could cause insomnia in someone her age?
ANSWER: Lots of children your daughter's age have trouble falling asleep easily at night. In many cases, the reason for this can be traced back to habits a child has developed that interfere with good sleep. Less often, it may be due to a sleep disorder.
Although it may seem helpful to let your daughter sleep in on the weekends, it actually disrupts her internal clock. That makes it much tougher to get back into a weekday sleep routine on Monday. Sleep deprivation then gets worse during the week.
Also, consider your daughter's use of electronic devices before bedtime. Many tweens and teens have televisions and computers in their bedrooms. They keep their cell phones close by at all times. These devices can make it hard to disengage from stimulating activities.
For the best sleep, children should turn off all electronic devices at least 30 to 60 minutes before bedtime. This gives the brain time to relax and wind down, making it easier to fall asleep. I strongly recommend that computers and TVs be kept out of a child's bedroom. It's best for cell phones to be shut down and stored in another room at night.
Your daughter should avoid any food or beverages that contain caffeine or sugar at least two to three hours before bedtime. Daily exercise and other physical activity can aid sleep. But have her finish those activities at least two hours before she goes to bed. Also, even if she is sleepy during the day, encourage her not to nap. Naps do more harm than good when it comes to getting good sleep because they often make falling asleep at night harder than ever.
For some children, when they lie down at night worries and concerns creep into their minds, making it hard to relax and fall asleep. To help clear her mind, it may be useful for your daughter to take a few minutes before bedtime to write down anything that's on her mind or tasks she needs to do. Once they're on paper, sometimes a child is better able to let their concerns go and get to sleep more easily.
Although it is not a common condition, another source of your daughter's problem could be a sleep disorder related to the workings of her internal, or biological, clock. The most common such problem at your daughter's age is called delayed sleep phase syndrome. Children who have this sleep disorder are "night owls." According to their internal clock, their day is longer than 24 hours. As a result, they tend to fall asleep at progressively later and later times each night and then have difficulty waking up in time to go to school.
It's important for your daughter's sleep problem to be addressed. Too little sleep can make it hard for a child to concentrate and pay attention at school. It can lead to mood swings and irritability, and can increase a child's tendency to accidents.
Try to first address any habits that may be interfering with your daughter's sleep. If changes in her habits don't help, make an appointment to see a sleep specialist to have her condition evaluated. -- Suresh Kotagal, M.D., Center for Sleep Medicine, Mayo Clinic, Rochester, Minn.
(Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care. E-mail a question to firstname.lastname@example.org. For more information, visit http://www.mayoclinic.org.)