(Kim Salt for The Washington Post)

Your child, no longer a baby, has trouble falling asleep. Or he wakes up in the wee hours of the morning and can’t get back to sleep.

Parents may worry if this happens more than occasionally. There’s all kinds of advice for helping babies sleep better, such as Ferberizing or baby whispering. But what’s the best way to help your older child?

Let’s start with the American Academy of Sleep Medicine’s advice. Young children, 3 to 5 years old, should sleep 10 to 13 hours, including naps, each 24-hour day; school-age children, 6 to 12 years old, should sleep nine to 12 hours; and adolescents, 13 to 18 years old, should sleep eight to 10 hours.

These recommendations were developed by a panel of experts who reviewed the scientific literature on sleep duration and health. Getting the recommended amount of sleep was associated with such things as improved attention and memory, better emotional regulation, and benefits for physical health. Conversely, getting less sleep was associated with behavior and learning problems, increases in accidents and injuries, and health problems such as hypertension, obesity, diabetes and depression.

The ranges are guidelines to be strived for but not obsessed over, experts say. “These are ballpark numbers,” says Judith Owens, director of the Center for Pediatric Sleep Disorders at Harvard University. “There are kids who are very comfortable on the lower end of the range. Others need the higher end of the range.”

There are other ways besides clocking the hours to assess whether your child is getting enough sleep, such as gauging how hard it is to wake them up in the morning, says Lisa Meltzer, a pediatric psychologist at National Jewish Health in Denver. Also, if a child sleeps in by more than two hours on weekends or falls asleep during school or during a short car ride, they might not be getting enough sleep. And then there are behavioral clues: “Following a night without good sleep, your child’s likely to be cranky or irritable,” Meltzer says. “Younger kids might be more hyper or overly difficult — having meltdowns.”

More and more, families are turning to melatonin for help. Owens says she’s seen “a huge uptick” in kids using melatonin for sleep problems. “Parents try it on their own or on the advice of their pediatrician,” she says. And yet, she adds, “we don’t have good efficacy data or safety data in children.”

A few studies on long-term melatonin use in kids, usually in children with attention-deficit/hyperactivity disorder or autism who are more likely to have sleep issues, have not found any obvious side effects. But they’re not ideal studies, Owens says, because they look for adverse effects after the fact, rather than evaluating subjects before treatment and then looking for changes with treatment.

Another problem is that melatonin is an unregulated over-the-counter supplement. This year, Canadian researchers tested 25 commercially available melatonin formulations and found that a tablet labeled as containing 5 milligrams might contain anywhere from 1 to 20 milligrams of melatonin. “So the consistency of over-the-counter products is very sketchy,” Owens says. (If you do want to try melatonin, Owens recommends parents go online and order “pharmaceutical brand melatonin” rather than buy an over-the-counter formulation.)

Still, melatonin can be a useful tool in combating sleep issues. “For most school-age kids, melatonin is a mild hypnotic, which means it makes you sleepy,” Owens says. She views the supplement as an adjunct, to be used alongside behavioral interventions, which are more effective and lasting. “But it’s acquired a reputation for being the go-to for insomnia,” she says. “The message for kids is, if you can’t sleep, take a pill.”

What else can parents do to help their kids sleep better? No. 1, says Meltzer, is to make sleep a priority for the whole family. It’s all too common to let bedtimes slide when life gets busy. Parents need to model this focus, not only enforce kids’ bedtimes.

“Children spend 40 percent of their lives sleeping,” Meltzer says, “It’s a huge portion, and it’s related to their health and well-being, as well as their academics and social interactions.”

Consistent sleep schedules are important, including parents setting bedtimes for their children — even teens. An Australian study asked 385 kids ages 13 to 18 to keep sleep diaries and found that kids whose parents set their bedtimes did indeed go to bed earlier and got more sleep. In a cross-cultural comparison, 17.5 percent of the Aussie teens said their parents set their bedtimes; only 6.8 percent of American teens reported the same.

Here’s the tricky part. Meltzer says those sleep schedules — bedtimes and wake-up times — should be maintained on weekends, too.

As a mom of teens, I pressed on this point. Meltzer gave me an out: “Maybe let a child go to bed one hour later and get up one hour later.” And it’s better to let a late night happen on Friday night, she says. “Wake up kids on Sunday morning. You want to keep them on their internal clock.”

To bolster her stand, Meltzer talked about the internal sleep pressure that builds up during the day. “Most teens need 14 to 16 hours of wakefulness before they’re ready to fall asleep. So you can let them sleep in, but that sets up a tough week.”

Other sleep-supportive measures are making sure bedrooms are cool, dark, comfortable and technology-free. Limit caffeine, especially after lunch. And make sure they get bright light in the morning: “Open those shades!” Meltzer says.

What if parents’ best efforts don’t help? Regularly having trouble falling asleep can be the first manifestation of an anxiety issue. Children who snore might have sleep apnea, which should get assessed. See your pediatrician about your concerns.