Although evidence is purely anecdotal, it appears these days that most children sleep a lot less than children of generations past. The majority of parents I encounter (certainly not all) seem to put their children to bed around the time they go to bed, which means a lot of kids out there may be getting only eight hours of sleep or less. Data presented in Weissbluth (2003), however, show that although total sleep per day declines with age until 14 years (in teenagers it creeps back up again), the median amount of sleep needed by children never drops below about 9.5 hours by this age. At 4, median sleep time is 12.5 hours, and the 10th percentile is 10.5. So although 10% of 4-year-olds out there may need less than 10.5 hours of sleep, one encounters many more than that who are getting less.

There seems also to be some correlation between sleep disorders and ADHD (attention deficit-hyperactivity disorder) (Gau et al., 2007; Hora das Neves 2007), although the nature of this correlation is not yet well understood, if it is even real (Sadeh et al., 2006). Medical studies relying on self- (or parental-) reported data, which many of these seem to be, are unreliable at best.

There are, however, suggestions by some that some of the people labeled as ADHD may instead be suffering from poor sleeping. This may be caused by sleep disorders such as sleep apnea. But most articles on the subject, even those advocating treatment of sleep disorders before treatment of the ADHD itself, seem to assume that sleep problems are one of the symptoms of ADHD.

What if the reverse is true, that years of sleep deprivation has caused ADHD? Weissbluth (2003) seems to be one of the few authors suggesting this link. All of us know that in the short term, sleep deprivation makes people irritable, unable to concentrate, and even often hyperactive. What if kids are growing up sleep-deprived for years? Might that not be a cause of sleep disorders?

What's worse is that the popular drug for controlling ADHD, Ritalin, is a stimulant, and kids on it sleep less than those on an alternative non-stimulant ADHD drug, atomoxetine. (Sangal et al., 2006). Are we making our kids lives worse in the long run by addressing only the short-term behavioral problems?

It can be difficult for parents to sleep-train their children, and many never do. Their child is in an endless cycle of exhaustion followed by a crash. The easiest way to sleep-train a baby is to put her down and let her cry until she falls asleep. Most kids will only cry for a long time for 2-3 nights, and then they understand that it is their sleep time, and they learn to put themselves to sleep. Failure to teach a child to get to sleep on his own can lead to a lifetime of sleep problems. It is crucial for the developing brain to get an adequate amount of sleep, which is when the brain processes new knowledge and experience. Babies and small children have a lot of new information to process, and they need to sleep a lot, often for longer than they are awake. It is not a stretch to imagine subtle (or not so subtle) developmental brain damage occurring in children who are chronically sleep-deprived because their parents will not force them to go to bed before they are exhausted. Obviously ADHD is a complicated issue, and it is likely to have many causes, ranging from genetic to environmental. But the first question any parent of a hyperactive kid should ask is, does my child get enough sleep?


References

Gau, S.S.F., Kessler, R.C., Tseng, W.L., Wu, Y.Y., Chiu, Y.N., Yeh, C.B. & Hwu, H.G. (2007) Association between sleep problems and symptoms of attention-deficit/hyperactivity disorder in young adults. Sleep 30:195-201.

Hora das Neves, S.N. & Reimao, R. (2007) Sleep disturbances in 50 children with attention-deficit hyperactivity disorder. Arquivos De Neuro-Psiquiatria 65:228-233.

Sadeh, A., Pergamin, L. & Bar-Haim, Y. (2006) Sleep in children with attention-deficit hyperactivity disorder: A meta-analysis of polysomnographic studies. Sleep Medicine Reviews 10:381-398.

Sangal, R.B., Owens, J., Allen, A.J., Sutton, V., Schuh, K. & Kelsey, D. (2006) Effects of atomoxetine and methylphenidate on sleep in children with ADHD. Sleep29:1573-1585.

Weissbluth, 2003. Healthy Sleep Habits, Happy Child. Ballantine Books, New York.

Labels: ADHD, brain, health, humans