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By Anne Harding
WEDNESDAY, March 4, 2009 (Health.com) — Children with attention-deficit hyperactivity disorder (ADHD) sleep less, spend less time in the rapid eye movement (REM) stage of sleep, and have a harder time falling asleep than youngsters without attention problems, according to new research published this week in the journal Sleep.
Experts say that making an extra effort to ensure a child gets enough sleep, such as being relatively strict about bedtimes, could help reduce his or her symptoms. “Be a detective, and look for what specifically is going on,” says Judith Owens, MD, who directs the pediatric sleep clinic and the ADHD clinic at Hasbro Children’s Hospital in Providence, Rhode Island, and was not involved in the new study. “It’s really important to try to uncover what the underlying issue is.”
However, parents should not expect better sleep to be a “miracle cure,” says Dr. Owens. The sleep problems are not considered to be a cause of ADHD, though they may add to a child's attention problems or difficulty with school; about 25% to 50% of children and adolescents with ADHD are thought to have difficulty sleeping.
In the new study, Reut Gruber, PhD, of McGill University in Montreal and her colleagues used portable polysomnography machines (which are usually only used in sleep labs) to monitor children at home as they slept in their own beds.
They looked at 15 children, 7 to 11 years old, diagnosed with ADHD and 23 children without the disorder, tracking how long it took them to fall asleep, how long they slept, and how much time they spent in each stage of sleep. Parents also filled out questionnaires on whether their child had sleep problems, such as anxiety about falling asleep and daytime sleepiness. None of the children were taking ADHD medication at the time of the study.
Next page: Kids with ADHD can be chronically sleep deprived
Overall, the kids with ADHD slept about a half-hour less, on average, and spent 15 fewer minutes in REM sleep. The control group spent about 19% of their sleep time in the REM stage, compared to about 17% for the ADHD group. The children with ADHD also took longer to fall asleep, were more anxious about sleep, and less likely to get enough sleep.
While REM is popularly thought of as the dream stage of sleep, it’s not absolutely clear why this sleep stage is important, Dr. Gruber notes. One possibility is that it has something to do with how our brains process information, she adds, but “we cannot be very certain about it.”
The researchers plan to look at other factors, such as circadian rhythm or changes in brain chemicals like dopamine and norepinephrine (which are known to play a role in sleep, attention, and arousal) that may link ADHD and sleep.
Children are different and the solution to their sleep problems can vary, says Dr. Gruber. “I don’t think at this point we can come with one recommendation that will address all of their needs.”
Next page: How you can help children sleep better
However, tried-and-true good sleep habits—such as setting a regular bedtime and enforcing it, having a bedtime routine that involves some quiet time before lights out, banning afternoon caffeine, and so on—may be enough for some families, Dr. Owens said, although it won’t necessarily be easy. “In a lot of these families the ADHD apple doesn’t fall far from the ADHD tree,” she said. “A lot of these households are very chaotic and kids don’t even have a bedtime.”
Other possibilities include adjusting a child’s medication to avoid an out-of-control period before bedtime, using relaxation techniques to help a child with bedtime-related anxiety prepare for sleep, or even giving a child light therapy to reset his or her circadian clock, says Dr. Gruber. Many researchers now believe that children with ADHD may have a “phase shift” that makes them feel ready to go to bed later at night than their peers, which makes it even more difficult to get up in the morning.
To find a doctor with the training to address sleep issues in children, Dr. Gruber recommends contacting the American Academy of Sleep Medicine, which offers a list of accredited sleep centers by location and certifies physicians in sleep medicine.
While the jury’s still out on whether improvements in sleep will translate to increased focus during the day, it will likely result in fewer signs of sleep deprivation—which can look a lot like ADHD.
“Every parent will tell you when their child doesn’t sleep they’re irritable and moody and inattentive,” says Mark Stein, PhD, the director of the ADHD Clinical Research Program at the University of Illinois at Chicago, who was not involved in Dr. Gruber’s study. “If they’re not getting adequate sleep or they’re not getting adequate REM sleep, that’s going to translate to how they’re going to function in school the next day.”
The Canadian Institutes of Health Research and the Fonds De La Recherche en Sante funded the study.