We all know what happens when a child misses a nap, stays up late or just doesn’t get a good night’s sleep. The next day he is irritable and probably gets into trouble more than on days when he did sleep well the night before. Even as a teen or adult, without the proper sleep you feel sluggish and have trouble focusing. When you or your child misses needed sleep, being overtired can show up as energy – in other words, hyperactivity. As any parent knows, there is a direct relationship between the lack of sleep and behavioral problems.
For years, doctors have been looking at the link between ADHD and sleep disturbances, trying to determine what causes what. For many with ADHD, both children and adults, sleep doesn’t come easily. It is hard to shut off a hyperactive mind in order to sleep. At the same time, sleep deprivation can mimic symptoms of ADHD. So what causes what?
- In 2002, Dr. Ronald Chervin, a neurologist and sleep researcher at the University of Michigan, found that, overall, children who snore are twice as likely to be inattentive and hyperactive. Boys under the age of 8 years old were four times more likely to have hyperactivity or attention issues. Snoring is usually caused by sleep apnea, which means you stop breathing for at least 10 seconds during sleep. According to the study, 22 percent of frequent snorers had high ADHD scores as compared to only 12 percent for infrequent snorers. 
- Dr. Chervin completed a follow-up study a few years later, again finding a link between poor sleeping and hyperactivity. The research team contacted the same participants four years after the study and found that those children who snored regularly were four times more likely to have develop hyperactivity than those who did not snore. Interestingly, snoring during the early years seemed a better predictor of hyperactivity than snoring during the follow-up four years later. 
- A new study, published in the March 2012 issue of the journal Pediatrics, looked at the sleep patterns of over 11,000 children from birth to age 7. Parents were asked to fill out questionnaires at six different times during the study and a behavioral assessment, the Strengths and Difficulties Questionnaire, was administered at ages 4 and 7. The study found that those children who had sleep apnea, snoring or other sleep-disordered breathing during infancy and early childhood had more behavioral problems later. By age 7, those with sleep difficulties were 1.5 times more likely to be hyperactive. 
Despite the results of these studies, a definitive link between sleep disturbances, snoring and ADHD is still elusive. For example, in the most recent study, other factors, such as prematurity, maternal smoking during pregnancy, and lower socioeconomic status were also found to be more common in children with hyperactivity.
Sleep apnea is often caused by problems with the tonsils and adenoids, which can be removed. It is still not understood if removing these and improving sleep will improve behavior, inattention and hyperactivity. Dr. Chervin, the lead author of the first two studies listed previously, is currently working on a new study that will look specifically at this issue, comparing children who have tonsillectomies/adenoidectomies with those that don’t, paying attention to whether sleep and behavior problems improve after this type of surgery.