Sunday, March 13, 2011

Sleep, Behavior, Hyperactivity and Attention in Children

If you ask the experts, they will tell you that approximately 9% of children in the US have the cluster of symptoms defined as ADHD.  5-16% of kids will have what is called "Oppositional Defiant Disorder," where kids deliberately break the rules, are quick to anger, and will often be sensitive and vindictive, among other problems.  Perhaps not surprisingly, these disorders overlap, with something like 50% or more of kids with ODD also having symptoms of ADHD.   It is also stressful and difficult to be surly and argumentative - 35% will also have a mood disorder, such as a depressive disorder.

I've already blogged quite a bit about the best research on the suspected links between diet and ADHD.  Kids diagnosed with ADHD were put on an anti-allergy diet (meat, vegetables, rice, water, pears and, for some, small amounts of wheat, potato, and other fruits), and 60% of them had significant improvement in ADHD and oppositional symptoms, which returned when they were switched back to the "healthy" control diet.  But another important behavioral link to ADHD is sleep quality.  It is known that kids with ADHD are poor sleepers in general compared to kids without ADHD, but what comes first?  Do the brain changes in ADHD screw up sleeping patterns, or do the sleeping pattern problems cause ADHD?  It may actually be a two way street for many, but a compelling recent line of research suggests that lack of sleep may be the causative issue for some kids.

First, some definitions.  There are basically three kinds of "sleep-disordered breathing" in kids:  obstructive sleep apnea (OSA - more common with obesity and allergy where kids get large tonsils and adenoids), upper airway resistance syndrome (UARS - probably also a structural or allergic phenomenon), and primary snoring.  There is also the relatively rare central apnea, where kids stop breathing and drop oxygen levels because the brain seems to forget to tell the lungs to work sometimes in sleep (happens with 10% of people on chronic opiate treatment for pain, too!  Scary.)  The difference between the obstructive and upper airway resistance apneas have to do with differences in how the diaphragm and chest work together to push the air out.  In both cases, the oxygen levels in the blood drop due to not getting enough air.  Do this all night, every night, and your brain gets to be a bit irritated with you.  Brain needs oxygen.  However, even kids who snore without dropping oxygen levels (the primary snorers) have more interrupted sleep and problems similar to those kids with OSA and UARS (1).

What kinds of problems?  Well, hyperactivity, poor attention, if young, lower scores on IQ tests, defiant behavior, poor grades.  Sounding familiar?  Interestingly, studies haven't consistently shown a connection between OSA and defiant behavior and low IQ in adults, though there are issues with inattention in adults (2).  In a study of kids with OSA who have surgery to remove the big floppy tonsils and adenoids that kept them from breathing properly (3), aggressive, inattentive, and hyperactive behavior significantly decreased following the surgery.   That's a pretty telling finding strongly suggesting that poor sleep in kids causes symptoms of ADHD and ODD.

In the German study of 1114 mostly Caucasian kids (1) from a random sample of schoolchildren, 114 ended up being habitual snorers, with most of that number ending up diagnosed with primary snoring, and a smaller number UARS and OSA.  It is interesting to me that number is pretty similar to the 9% overall prevalence of ADHD (though not all snorers had ADHD symptoms, and some never-snorers had ADHD symptoms).  

In the Cinncinati study of overweight older children and adolescents (2), it was noted that childhood obesity rates in 10-16 year olds have tripled in recent decades, to 16%, and minorities are overrepresented in this group.  13-39% of these obese kids will have sleep disordered breathing (SDB).  Among the obese kids without sleep problems, very few made the cut-off in this study for attentional problems, whereas of the kids diagnosed with SDB, 44% of them were defined by parents and 38% defined by teachers as having attentional problems.

To add yet another wrinkle, in a 2008 Yale study, 34 kids age 7-19 with metabolic syndrome and a positive sleep problem questionnaire were recruited to have sleep testing done.  25 of them ended up with sleep-disordered breathing, and those kids had higher sympathetic response (suggesting a raised level of overall stress, which eventually puts one at risk for all those diseases of inflammation, especially depression, anxiety, etc.) and higher leptin levels while insulin resistance was not elevated.  This is some evidence that leptin resistance occurs first, prior to insulin resistance, in the pathology of metabolic syndrome.  Treatment of the sleep-disordered breathing with a CPAP machine (a contraption that you wear at night to help you breathe better) for three months resulted in a near significant decrease in sympathetic activation, and a significant decrease in leptin levels.

Sadly, of a group of obese kids 4-20 years old, 38.7% of the moderately obese had metabolic syndrome , and 49.7% of the severely obese kids did.  Obesity in kids, as well as adults, is associated with hypertension, dyslipidemia, chronic inflammation, increased blood clotting, endothelial dysfunction, and high triglycerides.

The big picture - what is a common solution that would presumably help the inflammatory/allergy and the metabolic syndrome/obesity issues with oppositional behavior and attention in kids all at the same time?  Might it be that same old paleolithic-style diet I keep coming back to, along with regular exercise and dedication to proper sleep habits?   Killing all birds with one skillfully thrown stone, the evolutionary medicine lifestyle.  Again.


  1. If you haven't done so already, then I highly reccomend you read Dr. Dement's "The promise of sleep". Dement is the pioneering sleep researcher who helped designate the stages of sleep as well as identifying R.E.M sleep(strangely only discovered in the middle of the twentieth century). He devotes a number of pages to ADHD and sleep.
    Sleep and sleep wake cycles are also relevant to depression and all range of mood disorders(SAD etc.) Simply put if you don't sleep enough or your sleep wake cycles are off, you will be, at the very least, grumpy, and if you are succeptible to a mood disorder, exacerbating and/or causing a mental illness.
    I have a personal interest in this as for years(since the age of 13) I have dealt with extreme exhaustion. As I am young and thin, Sleep Apnea was never even considered as a possible explanation for me.
    In my twenties, after much frustration with my doctors who were totally useless, I pushed to have a sleep study done and found that I have sleep apnea. It is only now at 28 that that component of my exhaustion has been treated(I am still dealing with the same symptoms in spite of my sleep study showing that the apnea is properly treated)
    Interestingly, according to my current(and excellent) doctor who is both a Sleep specialist and a Psychiatrist, anti-depressants were once used as part of treatment for sleep apnea. The idea being that a lack of tone of the muscles(i.e collapsibility of the airway) could be remedied by a general toning up of the nervous system(e.g through norepenephrine levels).

  2. Emily this is a question that crossed my mind yesterday and I think you maybe the one to think about the answer and consequence. 3676 dead 7558 missing and rising. First time since WWII that dead/missing surpassed 10,000. Terrible for sure..... It is very sad. Yet, I am amazed at how the Japanese are handling this situation. Helping each other. No looting, no fighting, no killing. I have a theory why........their brains have higher levels of DHA from fish consumption and therefore their Fatty acid profile favors excellent neurotransmitter health in their frontal lobes......hence great behavior. We all saw what broke loose in American cities and in Haiti with stress....coincidence or not? I have thought about it much the last 48 hrs. I want to say its culture first but the diet angle is intriguing to me. What say you?

  3. John A - yes there are many slender folks with sleep apnea too, and another issue raised in some of the papers I read is that many children were treated for sleep apnea with the surgery when they were younger, but then did not follow up and still had apnea when they were older, but were unaware they had it.

    John - I am certainly no expert on Japanese culture. They do have quite a high suicide rate, though (21 per 100,000 per year compared to US 11 per 100,000 per year compared to some Catholic countries with a lot of stigma against suicide of 6-7 per 100,000 per year). A friend of mine lived in Japan for 9 years and told me (I don't know if this is true) that there are very few shoe sizes available in the stores - thats a strong cultural identity, no? They all could walk in each other's shoes. So they are all in this together, they support each other, it is too disrespectful and shameful to loot so that who would even think of it? And yet there is something about the culture that may diminish the importance of a
    single life, decreasing the dog eat dog survival animal behavior but maybe increasing the vulnerability to suicide? They had low low cholesterol but I think it is climbing - but DHA needs cholesterol to make a proper lipid raft on the
    neuronal cell membrane.... I don't have a good dietary answer for you!

  4. First, I would like to start by thanking you for your posts, especially the ones about AD(H)D. A lot of information online about ADHD comes without references of any sort. As a properly trained scientist I cannot accept anything there at face value. Here, you actually link to the studies and papers you base your findings on. Although I have no idea what most of the "tech-talk" means, its comforting and "Googable" if needed. The web is not just for LolCatz.

    I have a (hypothetical) question about the link between sleeping disorders, diet and ADD (I owe this to my poor mom, who actually developed her own sleeping disorder because of me).

    According to my mom, at three months old I wouldn't sleep more than six hours with the occasional five minute nap. These six hours were, as far as I can tell, divided between three hours in the morning after my dad went to work, and three in the evening. My mom recalls doing most of her ironing at 4 at night, under my watchful and wide-open eye. Years later my parents discovered that my gut stopped working when I was "vertical" and started again when "horizontal." This "start-up" hurt a lot and continued until I got some homeopathic stuff at age 8 that fixed it (not a clue what was in it, but it worked where years of "proper" medicine had failed." I still didn't need more than my trusty six hours of sleep until the age of 11.
    One day I slept in to 11 o'clock, with my poor parents downstairs, too scared to check if I was still alive. Since then, the situation has gotten worse, where some days I slept more than 15 hours without feeling refreshed. (There still seemed to be a 6-hour cycle in there somewhere as I woke up after 6, and fell asleep for another 6).

    At age 23 I got diagnosed with ADD and put on medication. At first it was great (no sleepy, yes concentration) but after a while the lack of sleep caught up with me again (yes sleepy, no concentration). After a couple of months of ritalin use I discovered I could no longer stand dairy made from cow-milk (but goat-milk's alright). Long story short: psych thought I was lactose-intolerant and even gave me lactose-free ritalin (apparently the "filler" for most medication is lactose, which seems like a rather odd choice since so many people are lactose-intolerant).

    I realize that my traditionally bad sleeping habits,lack of exercise, poor diet and boredom with my never-ending MA thesis (did you already guess from the length of this post?), are behind the lack of concentration I experience today. But I wonder if it's not the end result of some sort of food-allergy that presented itself fairly soon after birth, manifesting itself in poor sleeping habits, which in turn created a cycle I haven't been able to break in almost 30 years. (bad sleep -> no energy -> ADD-like problems, such as providing for ones nutritional intake -> rince and repeat).

    After reading your blog I'm sure there are a number of people with AD(H)D who have these problems (cite: this blog) and I wonder if it would be possible to differentiate between AD(H)D'ers based on their "entry-point" in this cycle. Could this be one of the reasons there is so much diversity in "succesful" treatments? Or why the medical world has failed to find a diagnostic tool more reliable than the DSM criteria? To me, it also seems like a plausible explaination to the question why some "outgrow" ADHD and others are professor chaos for the rest of their lives.

    Thoughts? Anyone?

  5. @John: as I am supposed to be a semi-expert on South-East Asia due to many, many years of lingering around the anthropology department: I don't know about chemistry of the Japanese/US brain, but I suspect the issue here is culture first. The US, as most "Western countries" (I won't bore you with the anthropological no-no's surrounding the use of words like "Western" and "countries" or even "culture") have a much more individualistic society than most "non-western" countries. In a country where it is considered rude to say "no" or even "I don't know," and where structure and social position are relentlessly adhered to; can you imagine what it means to go out looting, killing and fighting on a massive scale? Japan has displayed that they feel the needs of the many outweigh the needs of the few (very Spock in Wrath of Khan of them). Take for instance Seppuku (hara-kiri) or kamikaze-pilots. The high rate of suicides is thought to flow from this, exacerbated by the immense pressure on Japanese citizens. People work very long hours and often 6 or 7 days a week. Every misstep is accounted for. If you do not well in pre-school, you wont get into any good schools after that and will not land the job of your dreams. A friend of mine who studies Japanese, even told me that Japanese try to get a job at the biggest company they can find, as they are expected to stay with that company the rest of their lives. Smaller companies have less opportunities for promotion. And you need a good job to bring pride to your family and buy a big house, cause your aging parents are gonna move in with you and expect to be taken care of.
    Personally, I'd take individual choice and the ability to fall flat on my ass without wrecking my life over the nobility of not looting, fighting and killing your neighbor during crisis. And from what I've gathered, the Japanese were heading our individual way right before the earthquake. Would be interesting to see how Japanese society will be affected in this regard.
    No time for proper references but here's a wiki-page:
    Also check the part where they suggest a link with popular culture. If you find this interesting, make sure you watch this movie: . Don't forget to read up on the interpretations of this film. very interesting

    (two posts I know.. My original was too long)


Tired of receiving spam comments! Sorry, no new comments on the blog

Note: Only a member of this blog may post a comment.