Category Archives: Sleep

Creating slow-wave sleep on demand

Press-release just in – Deep Sleep: Researchers Discovery How To Simulate Slow Wave Activity:

During slow wave activity, which occupies about 80 percent of sleeping hours, waves of electrical activity wash across the brain, roughly once a second, 1,000 times a night. In a new paper being published in the scientific journal PNAS, Tononi and colleagues, including Marcello Massimini, also of the UW-Madison School of Medicine and Public Health, described the use of transcranial magnetic stimulation (TMS) to initiate slow waves in sleeping volunteers. The researchers recorded brain electrical activity with an electroencephalograph (EEG).
A TMS instrument sends a harmless magnetic signal through the scalp and skull and into the brain, where it activates electrical impulses. In response to each burst of magnetism, the subjects’ brains immediately produced slow waves typical of deep sleep, Tononi says. “With a single pulse, we were able to induce a wave that looks identical to the waves the brain makes normally during sleep.”
The researchers have learned to locate the TMS device above a specific part of the brain, where it causes slow waves that travel throughout the brain. “We don’t know why, but this is a very good place to evoke big waves that clearly travel through every part of the brain,” Tononi says.
Scientists’ interest in slow waves stems from a growing appreciation of their role in sleep, Tononi says. “We have reasons to think the slow waves are not just something that happens, but that they may be important” in sleep’s restorative powers. For example, a sleep-deprived person has larger and more numerous slow waves once asleep. And as sleep proceeds, Tononi adds, the slow waves weaken, which may signal that the need for sleep is partially satisfied.
Creating slow waves on demand could someday lead to treatments for insomnia, where slow waves may be reduced. Theoretically, it could also lead to a magnetically stimulated “power nap,” which might confer the benefit of eight hours sleep in just a few hours.
Before that happens, however, Tononi must go further and prove that artificial slow waves have restorative benefits to the brain. Such an experiment would ask whether sleep with TMS leads to greater brain restoration than an equal amount of sleep without TMS.
Although an electronic power-napper sounds like a product whose time has come, Tononi is chasing a larger quarry: learning why sleep is necessary in the first place. If all animals sleep, he says, it must play a critical role in survival, but that role remains elusive.

Once the paper shows up on the PNAS site, I’ll see if there is more I need to add to this story.

Do whales sleep?

It is Marine Megavertebrate Week right now, so why not take a look at one of the most Mega of the Megaverts – the grey whale (Eschrichtius robustus):
Do whales sleep? You may have heard that dolphins do – one hemisphere at the time, while swimming, and not for very long periods at a time. A combined Russian/US team of researchers published a study in 2000 – to my knowledge the best to date – on sleep-wake and activity patterns of the grey whale: Rest and activity states in a gray whale (pdf) by Lyamin, Manger, Mukhametov, Siegel and Shpak.

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Good. Everyone expected it, but it is nice to have it tested and confirmed. Makes life easier and research cheaper.
Measuring Movement To Assess And Manage Sleep Disorders:

Actigraphy, the use of a portable device that records movement over extended periods of time, and has been used extensively in the study of sleep and circadian rhythms, provides an acceptably accurate estimate of sleep patterns in normal, healthy adult populations and in-patients suspected of certain sleep disorders, according to practice parameters published in the April 1st issue of the journal SLEEP.

This means that patients can go about their normal lives instead of checking into a sleep lab. They just need to wear the “watch” at all times and bring/send in the data on a regular basis.

Sleepwalking as an Alibi

Sandra has a post about an interesting case of a person who commited a crime (and was acquitted) while sleepwalking. The term “sleep disorder” was used as a defence.
But, is it a disorder at all? It naturally occurs in a proportion of human population. It is called a disorder because it does not happen to everyone and it can be dangerous for the sleepwalker or the people around him/her. Nobody is really trying to treat it, except for making sure that habitual sleepwalkers have a safe environment in which to walk at night (multiple complicated locks on the doors, etc).
Yes, you are completely unconscious, you cannot plan what to do once you are asleep and walking, you have no awareness of what you are doing while you are sleepwalking, and you have no recollection of what you did once you wake up. This would make acquittal a correct decision, without any need to invoke a ‘disorder’.
Yet, a person who would commit crime when awake will commit one when sleepwalking, and person who would never do so while awake is unlikely to get started while asleep.
Michael Rack does not have much on the topic on his blog, and neither does Michael Breus, but there is more here.
This is also similar to the case of sexsomnia.
So, what do you think? Is this a good alibi? If you did something bad while unconscious, would you want to be acquitted?

PERIOD clock gene variants affect sleep need in humans

The most exciting thing about this study is that this is, as far as I am aware, the first instance in which it was shown that a circadian clock gene has any effect on sleep apart from timing of it, i.e., on some other quality or quantity of sleep (not just when to fall asleep and wake up, but also the depth of sleep and the amount of sleep need):
Performing Under Sleep Deprivation: Its In Your Genes:

People are known to differ markedly in their response to sleep deprivation, but the biological underpinnings of these differences have remained difficult to identify.
Researchers have now found that a genetic difference in a so-called clock gene, PERIOD3, makes some people particularly sensitive to the effects of sleep deprivation. The findings, reported by Antoine Viola, Derk-Jan Dijk, and colleagues at the University of Surrey’s Sleep Research Center, appear in the journal Current Biology, published by Cell Press.
There are two variants of the PERIOD3 gene found in the human population, encoding either long or short versions of the corresponding protein. Each individual will possess two copies of the gene, either of which might be the long or short form. Previous work had indicated that the different forms of the gene appear to influence characteristic morning and evening activity levels–for example, “owl” versus “lark” tendencies.
In the new work, a multidisciplinary research team consisting of biological scientists and psychologists compared how individuals possessing only the longer gene variant and those possessing only the shorter one coped with being kept awake for two days, including the intervening night. The researchers found that although some participants struggled to stay awake, others experienced no problems with the task.
The results were most pronounced during the early hours of the morning (between 4 and 8 a.m.), during which individuals with the longer variant of the gene performed very poorly on tests for attention and working memory.
The authors point out that this early-morning period corresponds to stretches of time when shift workers struggle to stay awake, during which many accidents related to sleepiness occur. But the scientists also emphasize that the new research was conducted in the laboratory, and whether forms of the PERIOD3 gene also predict individual differences in the tolerance to night-shift work remains to be demonstrated.
An additional finding was that the effects of this gene on performance may be mediated by its effects on sleep. When the volunteers were allowed to sleep normally, those possessing only the longer form of the gene spent about 50% more of their time in slow-wave sleep, the deepest form of sleep. Slow-wave sleep is a marker of sleep need, and it is known that carrying a sleep debt makes it very difficult to stay awake and perform at night.
The findings highlight a possible role for clock genes in human sleep physiology and structure, and the influence these genes might have on performance by unrested individuals.

Sleep deprivation halts creation of new neurons in the hippocampus

This is interesting:
Study: Sleep linked to brain cell creation:

The Proceedings of the National Academy of Science research on rats found that the hippocampus portion of the brain was directly affected by a lack of sleep for a long period, the BBC reported.
By depriving rats of sleep for 72 hours, the researchers found that those animals consequently had increased amounts of the stress hormone corticosterone, and produced significantly fewer new brain cells in the hippocampus.
When the rats’ sleep patterns were returned to normal a week later, their levels of nerve-cell production remained hindered for two weeks.
The lack of production appeared to prompt the brain to increase its efforts to maintain an appropriate balance.
British sleep expert Dr. Neil Stanley called the finding “interesting,” but said more study on sleep depravation might be useful.
“It would be interesting to see if partial sleep deprivation — getting a little bit less sleep every night than you need — had the same effect,” he told the BBC.

But does that have anything to do with memory?

Quality of Wakeful Life affects the Quality of Sleep

Slow-wave Activity During Sleep Affected By Quality, Intensity Of Wakefulness:

A study published in the February 1st issue of the journal SLEEP provides a first direct demonstration that the “quality” and “intensity” of wakefulness can affect slow-wave activity (SWA) during subsequent sleep.
According to Chiara Cirelli, MD, PhD, of the University of Wisconsin-Madison, one of the authors of the study, the importance and novelty of the paper lies in the demonstration that the crucial factor linking physiological waking activity to sleep SWA is synaptic plasticity, notably synaptic potentiation, mediated by brain-derived neurotrophic factor (BDNF) signaling.
“Namely, the study shows that wakefulness associated with exposure to an enriched environment and with high levels of exploratory activity, a condition well known to trigger plastic changes in the brain, leads to increased BNDF expression and increased sleep pressure as compared to wakefulness with low exploratory activity,” said Cirelli. “More stringently, the study finds that the amount of exploratory behavior during wakefulness can predict the extent to which BDNF is induced in the cerebral cortex, as well as the extent of the SWA response during subsequent sleep.”

This feeds very nicely with the excellent paper I reviewed recently.
Also, what does it say about the erotic dreams? And yes, I will review the companion paper on the sexual content of daydreaming as well.

New potential sleeping pill

If you discover a brain chemical which, when missing or malfunctioning (due to a mutation in its receptor) abruptly puts people and animals to sleep when they don’t want to – a condition called narcolepsy – then you can work on creating a drug that acts in the opposite way and induces sleep when you want to.
Apparently, that is what a Swiss team just did (Nature news report here and Nature blog commentary here). The drug, still without a sexy name, is known by its “code-name” ACT-078573.
The target of the drug is the orexin system. Orexins (also known as hypocretins – the discovery was simultaneous in two laboratories several years ago and both terms are in equal use in the literature – you may remember one of the studies as it received some media coverage because it tested narcoleptic Doberman pinchers) are two closely related neuropeptides (orexin 1 and orexin 2). They are produced by cleavage of a single precursor protein. They are strongly conserved through the vertebrate evolution. They are produced in a small cluster of nerve cells, but those cells make projections widely across the brain.
The major function of orexins is to integrate circadian, sleep and metabolic information to determine if the animal should be awake or asleep. The connection to metabolism is also responsible for a secondary role of orexins in the control of appetite.
In narcoleptic people (or dogs), the levels of orexin are very low, or the orexin receptor is not functioning. In other words, the funciton of orexins is to promote wakefulness. ACT-078573 is an orexin antagonist – it blocks effects of orexin, thus promoting sleepiness.
It is too early to talk to your physician about this drug yet. This was just a first preliminary study. The drug was given only once, so we do not know possible effects of prolonged use. It was given to 42 healthy males with no history of sleep disorders, thus we do not know how it would effect women, children or people WITH sleep disorders – exactly those who would potentially benefit from this drug.
Just because a single use did not provoke other symptoms of narcolepsy – loss of muscle tone, loss of coordination and hallucinations – does not mean that long-term use of the drug would not result in such side-effects (after all, even the early narcoleptic events in affected people do not usually have such side-effects – they develop over time).
Another consideration is timing. In the study, the drug was given during the day when the orexin levels are naturally high (remember – orexin promotes wakefulness). We do not know what effect, if any, the orexin antagonist would have at night when orexin levels are naturally low. After all, as with all drugs targeting the circadian system, the effect is highly dependent on timing.
Another concern is with a possible side-effects of the drug on the appetite. Though this may be turned into a positive for the drug if it can be shown to be useful in control of appetite. Nothing sells better than sleep pills except the diet pills, after all!

The Cultural Politics of Sleep

Nicole Eugene recently defended her Masters Thesis called Potent Sleep: The Cultural Politics of Sleep (PDF) on a topic that I find fascinating:

Why is sleep, a moment that is physiologically full and mentally boundless, thought to be a moment of absence and powerlessness? Where did this devalued notion of sleep come from and how can we situate sleep studies within a continuation of a historical processes and economic infuences? In other words, how does sleep effect and exist within systems of power? To answer these questions I turn to a range of scholarship and theoretical studies to examine the complexities and dynamics at work within the cultural discourses on sleep. By creating a genealogy of sleep I am able to track the way notions of sleep have changed and evolved over time. I develop a theoretical framework to examine how the Enlightenment effected notions of sleep by strengthening a cultural disposition for logical, rational and phonomenological modes of knowledge. I find that the advent of modernity is signified by the moment in which sleep, darkness and unknowing become negative while being awake, light and knowledge become positive. To understand how sleep (and sleep studies) operates in contemporary situations I examine them within the economy of time in which clock time is conflated with money. Here I also visit the way sleep functions in relation to work in a neo-Taylorist management era. I offer an account of sleep’s connections to passivity within the patriarchal systems of thought. I determine that the cultural politics of sleep and sleep disorders point to a rift in the Western Self because of a presumed simultaneity of thinking, acting and being. I have engaged in a range of disciplines and use theory, historical studies, textual analysis , and autoethnography as methodologies to outline some of the major cultural discussions that surround sleep.

And she is not the only one in the world interested in cultural, social and political aspects of sleep. I wish someone would pay for me to go and liveblog the Workshop: New Directions in the Social and Cultural Study of Sleep to be held in Vienna on 7-9 June 2007:

This international and interdisciplinary workshop aims at exploring new directions in the study of sleep from the perspectives of the Humanities, Social and Cultural Sciences. The aim is to raise awareness of the social, cultural, political, and environmental influences on sleep behaviour and to describe in detail variations of sleep patterns in different countries and social groups as well as the meanings people attribute to their sleep and sleep-related behaviour.

Once I read the 191 pages of Nicole’s thesis (and I’ll have to find some time to do it), I will post my thoughts on it here, so stay tuned.

This aired too early in the day for my adolescent brain…

I was too busy with the conference so I missed the NPR Morning Edition story on one of my favourite subjects: Adolescent Sleep, which was followed by two more stories on the same subject! I am glad to see this topic becoming this prominent.
Hat-tip: Mind Hacks

Sleep Deprivation – Societal Causes and Effects

Sleep Deprivation - Societal Causes and EffectsHere is the second guest-post by Heinrich (from March 20, 2005):

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What are Dreams for?

Jonah has a good rundown on a new paper on the neuroscience.

What Is Sleep For?

What Is Sleep For?Back in March 2005, I asked Heinrich of the She Flies With Her Own Wings blog to guest-post on Circadiana. He wrote two nice posts and this is the first of them (March 18, 2005). Perhaps I can get him to do some more…

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Puffy ankles? You may get sleep deprived.

Fluid Displacement From Legs To Neck Can Lead To Obstructive Sleep Apnea:

When a person lies down, a small amount of fluid displaced from the legs to the base of the neck can narrow soft tissue around the throat and increase airflow resistance in the pharynx by more than 100 percent, predisposing the person to obstructive sleep apnea.
In obstructive sleep apnea, a blockage in the throat or upper airway causes victims to repeatedly stop breathing long enough to decrease the amount of oxygen in the blood and increase the carbon dioxide.
“Our data show that displacement of a small amount of fluid such as 340 ml, about 12 ounces, from the legs is sufficient to cause a 102 percent increase in airflow resistance of the pharynx in healthy, non-obese subjects,” continued Dr. Bradley

These were healthy, non-obese people without sleep apnea. Presumably, even more fluid would be shifted in obese people, and the effect would be an even greater restriction of the airways in people already predisposed to sleep apnea (snorers, for instance).
So, should you sleep with your head raised and your feet lowered? Do astronauts in zero-gravity suffer from sleep apnea?

The link between sleep and memory, from a somewhat different angle.

Memory Improves After Sleep Apnea Therapy:

Patients with obstructive sleep apnea (OSA) may improve their memory by using continuous positive airway pressure (CPAP). A new study published in the December issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP), shows that the majority of patients with OSA, who were memory-impaired prior to treatment, demonstrated normal memory performance after 3 months of optimal CPAP use. The study also showed that memory improvement varied based on CPAP adherence. Patients who used CPAP for at least 6 hours a night were nearly eight times as likely to demonstrate normal memory abilities compared with patients who used CPAP for 2 or fewer hours a night.

Sleep apnea is a condition in which airways close and induce a temporary brief awakening. Patients are, thus, unable to go through normal cycles of sleep phases, resulting in, effectively, sleep deprivation. This study is a nice additional evidence for the importance of sleep in learning and memory.

New York Times Gets It Right, Just To Screw Up At The End In Blind Adherence To The He Said/She Said Journalism

New York Times Gets It Right, Just To Screw Up At The End In Blind Adherence To The He Said/She Said JournalismNow behind the Wall, but plenty of excerpts available in this March 26, 2005 post…

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A vicious cycle of alcohol and insomnia

Recovering alcoholics with poor sleep perceptions will likely relapse:

“The usual perception of alcohol’s effects on sleep in nonalcoholics is that it helps sleep,” explained Deirdre A. Conroy, the corresponding author who conducted the research while a postdoctoral fellow at the University of Michigan. “In truth, alcohol may help people fall asleep but it usually leads to poor quality sleep in the second half of the night and overall less deep sleep. As people drink more regularly across nights to fall asleep, they become tolerant to the sedating effects of alcohol and subsequently use more alcohol each night to help fall asleep. This escalation in drinking can lead to alcoholism.”

Waking Experience Affects Sleep Need in Drosophila

Blogging on Peer-Reviewed Research

There is nothing easier than taking a bad paper – or a worse press release – and fisking it with gusto on a blog. If you happen also to know the author and keep him in contempt, the pleasure of destroying the article is even greater.
It is much, much harder to write (and to excite readers with) a blog post about an excellent paper published by your dear friends. But I’ll try to do this now anyway (after the cut).

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An Excellent Article about Sleep

Sleep: it’s required:

“….short sleep can hasten the arrival of the inevitable long sleep”

Good Article On Sleep

Occasionally, an article on sleep in the newspapers is actually good. Like this one.

No all-nighters for you!

Shelley went to the Society for Neuroscience meeting and saw a talk on sleep deprivation, memory and hippocampus.

It’s all connected – sleep, hunger, obesity

Shorter Nightly Sleep In Childhood May Help Explain Obesity Epidemic:

This research shows that shorter sleep duration disturbs normal metabolism, which may contribute to obesity, insulin resistance, diabetes, and cardiovascular disease. Even two to three nights of shortened sleep can have profound effects, the laboratory data suggest.
One study indicated that insufficient sleep at the age of 30 months was associated with obesity at the age of 7, suggesting that this could programme the part of the brain regulating appetite and energy expenditure, says Dr Taheri.
Another piece of research shows that levels of leptin, a hormone produced by fat tissue when energy stores are low, were more than 15% lower in those sleeping five hours compared with those clocking up 8.
Similarly, ghrelin, a hormone released by the stomach to signal hunger was almost 15% higher in those with a five hour sleep quota.
Sleep loss also disturbs other hormones, including insulin, cortisol (stress hormone), and growth hormone, says Dr Taheri, who adds that hormonal changes could boost the desire for carlorie rich foods.
And poor sleep sets up a vicious cycle. It leads to fatigue, which leads to reduced levels of physical activity….which leads to lower energy expenditure…..which leads to obesity, which itself leads to poor sleep, he adds.
Dr Taheri acknowledges that the mechanisms behind obesity are likely to be complex. “Sleep is probably not the only answer to the obesity pandemic, but its effect should be taken seriously, as even small changes in energy balance are beneficial,” he says.

Related: Sleep yourself skinny:

An interesting article has recently come out in the journal, Obesity Reviews. In it the authors talk about how much weight you can lose by just adding 1 more hour of sleep to your day.

Sleep in Infants

I tend to rant about sleep in adolescents for various reasons, but other people focus on other age groups. Infants are one such group, interesting because it takes a while for their circadian rhythms to consolidate resulting in “sleeping through the night”.
For years, the only serious book on the topic was Ferber, much maligned for its advice to “let them cry it out”, though the rest of the book is correct and informative. Apparently, there is a good new book on the topic – The No-Cry Sleep Solution: Gentle Ways to Help Your Baby Sleep Through the Night (as well as The No-Cry Sleep Solution for Toddlers and Preschoolers by the same author, Elizabeth Pantley).
Also, Ferber has issued a new edition of his book in which he gives up on the “cry it out” strategy and gives more space to the issue of bed sharing.

What is a ‘natural’ sleep pattern?

What is a 'natural' sleep pattern?Nothing too complicated today, but something you should all know (from March 13, 2006).

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It’s not the quantity, but timing

Study says no video games on school nights:

According to Dr. Iman Sharif, the results were clear-cut. “On weekdays, the more they watched, the worse they did,” said Dr. Sharif. Weekends were another matter, with gaming and TV watching habits showing little or no effect on academic performance, as long as the kids spent no more than four hours per day in front of the console or TV. “They could watch a lot on weekends, and it didn’t seem to correlate with doing worse in school,” noted Dr. Sharif.

The study was using self-reporting by kids, which has its problems, but is OK in this case, I think. The key information they did not gather was the timing of game-playing and TV watching.
On schooldays, the only time they can do this is late in the evening, after homework and dinner and sports and everything else have been done. Exposure to light from the screens, as well as the emotional involvement (perhaps raised adrenaline?) phase-delays the kids’ already delayed circadian clocks. Instead of getting 9 hours of sleep, they get 5 or 6. Of course they perform miserably at school and the athletic field, feel lousy and misbehave – they are chronically sleep-deprived.
On weekends, kids are likely to play and watch in the morning or early afternoon, which does not affect the phase of their sleep-wake cycle.
I let my kids play games first thing when they come home from school. They do homework later – it gradually puts them to sleep so they are not sleep deprived.
Hat-tip: Ed Cone.

(Non) Adaptive Function of Sleep

(Non) Adaptive Function of SleepFrom November 01, 2005, a review of a review…

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Circadian Rhythm of Caffeine Effects

Since every chemical induces a different response in the body dependent on the time of day when it is administered, I am not surprised that this also applies to caffeine:

A new study at the Université de Montréal has concluded that people drinking coffee to get through a night shift or a night of studying will strongly hurt their recovery sleep the next day. The study published in the current issue of Neuropsychopharmacology was conducted by Dr. Julie Carrier from the Department of Psychology at the Université de Montréal. Dr. Carrier runs the Chronobiology Laboratory at the Hôpital du Sacré-Coeur de Montréal.
“We already knew that caffeine has important effects on nocturnal sleep. It increases the time taken to fall asleep, it increases the amount of awakenings, and it decreases the amount of deep sleep. We have shown that these effects of caffeine on sleep are way stronger when taken at night prior to a daytime recovery sleep episode than in the evening before a nocturnal sleep episode.”
“Caffeine makes daytime sleep episodes too shallow to override the signal from the biological clock that tells the body it should be awake at this time of day,” explains Dr. Carrier. “We often use coffee and other sources of caffeine during the nighttime to counteract sleepiness generated by sleep deprivation, jet lag, and shift-work. However, this habit may have important effects when you then try to recuperate during daytime.”
Thirty-four moderate caffeine consumers participated in both caffeine (200 mg) and placebo (lactose) conditions in a double-blind crossover design. Seventeen subjects followed their habitual sleep–wake cycle and slept in the laboratory during the night (Night), while 17 subjects were sleep deprived for one night and recovery sleep started in the morning (DayRec). All subjects received a capsule of 100 mg of caffeine (or placebo) 3 hours before bedtime, and the remaining dose 1 hour before bedtime. Compared to placebo, caffeine lengthened sleep latency, increased stage 1, and reduced stage 2 and slow-wave sleep (SWS) in both groups. However, caffeine reduced sleep efficiency more strongly in the DayRec group, and decreased sleep duration and REM sleep only in that group.

Viagra keeps you up at night

No, not (just) that part – your brain. A new study shows that a single dose of Viagra makes symptoms of sleep apnea worse. And sleep deprivation resulting from sleep apnea may be one of the reasons why you may need Viagra in the first place. What a vicious circle! What a conundrum! Sleepdoctor has the goods.

New issue of the journal SLEEP

You can see some highlights here.

Alternative sleep therapies

Over 1.6 Million Americans Use Alternative Medicine For Insomnia Or Trouble Sleeping:

A recent analysis of national survey data reveals that over 1.6 million American adults use some form of complementary and alternative medicine (CAM) to treat insomnia or trouble sleeping according to scientists at the National Center for Complementary and Alternative Medicine (NCCAM), part of the National Institutes of Health.
Those using CAM to treat insomnia or trouble sleeping were more likely to use biologically based therapies (nearly 65 percent), such as herbal therapies, or mind-body therapies (more than 39 percent), such as relaxation techniques. A majority of people who used herbal or relaxation therapies for their insomnia reported that they were helpful. The two most common reasons people gave for using CAM to treat insomnia were they thought it would be interesting to try (nearly 67 percent) and they thought CAM combined with a conventional treatment would be helpful (nearly 64 percent).

I don’t really know what to think. On one hand, someone is making a lot of money on this. On the other hand, placebo effect may be quite effective for relaxing a person enough to fall asleep. Meditation certainly will help a person relax – it is so boring you have to fall asleep after a while. And who knows, one of those therapies may actually have some effectiveness after all – we don’t know because it was never tested. On the other hand, many herbal remedies, because they are never tested and approved, may contain some nasty chemicals that can kill you. Such deadly molecules were discovered in some brands of melatonin a few years back. So, they are not safe even if they are effective. I’d like to see Orac and Abel comment on this.

In addition to looking at the data on CAM use and insomnia, the researchers also looked at the connection between trouble sleeping and five significant health conditions: diabetes, hypertension, congestive heart failure, anxiety and depression, and obesity. They found that insomnia or trouble sleeping is highly associated with four of the five conditions: hypertension, congestive heart failure, anxiety and depression, and obesity.

All of those connecitons have been seen before and some of those have been studied in quite a lot of detail. Unfortunately, there appears to be a vicious cycle – these conditions negatively affect sleep and lack of sleep negatively affects these conditions.

New Sleep Articles

The latest issue of Archives of Internal Medicine is devoted to sleep. The articles are freely available. Here is the press release:
Incorporate Sleep Evaluation Into Routine Medical Care, Expert Says

Sleep is an integral part of health, and assessment of sleep habits should be a standard part of medical care, according to an editorial in the September 18 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. The issue is devoted to studies of sleep and health.
“The theme that emerges throughout this issue is that sleep serves as an indicator of health and quality of life and therefore is highly and directly relevant to the practice of medicine,” write guest editor Phyllis C. Zee, M.D., Ph.D., and Fred W. Turek, Ph.D., of Northwestern University Feinberg School of Medicine, Chicago.
“Indeed, numerous studies have recently shown that sleep disorders are often comorbid with a broad range of medical and psychiatric conditions and also have a negative impact on health, mood and quality of life,” they continue. “Increasing evidence also points to a bidirectional relationship between sleep and health; that is, sleep disturbances contribute to the development of or increase the severity of various medical and psychiatric disorders, and these same disorders result in poor sleep quality.”
Research results published in this issue of Archives of Internal Medicine “further our understanding of the relationship of sleep and health,” Drs. Zee and Turek write. Studies appearing in this issue find that:
* Fewer hours of sleep may contribute to poor health in young adults, according to an international survey of more than 17,000 university students
* Those in rural areas who sleep fewer hours appear to have a higher average body mass index
* The immune system may play a role in narcolepsy, a disorder marked by a sudden and uncontrollable urge to sleep
* Children with chronic illnesses, especially those on ventilators, tend to have parents with disrupted sleep
* The immune system may be affected by a lack of sleep, altering blood chemistry in a way that potentially contributes to inflammation and a variety of diseases
Over the past decade, it has become apparent that voluntarily limited sleep, as well as sleep disorders such as insomnia and restless legs syndrome, can negatively affect overall health–a connection emphasized by the increasing legitimacy of sleep medicine as a specialty. In addition, medications used to treat a number of physical and psychiatric disorders can affect sleep, making evaluation for sleep problems essential for those following such regimens. “At the very least, assessment of sleep quantity and quality should be integrated into the routine review of systems,” Drs. Zee and Turek conclude. “Sleep is an indicator of health, and sufficient sleep quantity and good quality should be considered as an essential component of a healthy lifestyle, as much as exercise and nutrition.”

Wide Awake

I feel a professional duty to watch – once it is available – and review this movie about sleep deprivation and insomnia. Sounds pretty good and informed, as well as entertaining, at least according to the article:

Night after night for some 40 years, the US independent filmmaker, Alan Berliner, has battled with his sleep demons.
He has tried everything to defeat them, including meditation, acupuncture, herbal remedies, “lots of sex” and earplugs.
Recently, he made Wide Awake, a film investigating both insomnia in general, and his affliction in particular. In the film, we watch as night vision cameras capture his nightly torment.
He says the process of making the film “induced, over time, a kind of madness”, and his mother suggests on camera that the process is damaging him. “Night after night I am watching myself watch myself not be able to sleep,” Berliner says of the 18-month project. “Each night, going to bed was a research opportunity. And that can be tiring.”

Sleep Deprivation in the classroom, in the cockpit and on the space shuttle

Students not getting enough sleep:

College students may believe they are being more productive when they sleep less, but in reality it is causing harm to their bodies. The National Sleep Foundation points out that receiving less than six hours of sleep a night is associated with 1.7 times greater risk of disease, according to The chance of decreased academic performance, driving accidents, colds and flu and mental illnesses are all increased.

Workplace fatigue risky business at 30,000 ft.:

Fatigue is worsened when lack of sleep is coupled with a disruption to the body’s circadian rhythm, which regulates high and low energy periods throughout the day – common among flight and ground crews as well as controllers.
And it’s also magnified by jetlag. One U.S. sleep researcher estimates 96 per cent of airline pilots and flight attendants operate in a permanent state of jetlag.

Solar wings unfurl on Atlantis orbit:

“On our mission, with where the sun is, we have 55 minutes of daylight followed by 75 minutes of darkness … and that does affect your circadian rhythm,” MacLean replied.

Rich people sleep better

I’ve heard of this before, but now I see an actual study has been published:

There’s more to a good night’s rest than going to bed early. Sleeping comes easiest and lasts longest for the wealthy, white, and female. Reporting her findings in the June 1 American Journal of Epidemiology, health-studies associate professor Diane Lauderdale, AM’78, AM’81, followed the sleep habits of 669 Americans aged 35 to 50 and found that those with a yearly income of less than $16,000 spend longer in bed than those making $100,000 or more, but they sleep less because their “sleep latency,” the amount of time spent lying in bed awake, stretches to nearly an hour.


Using both self-kept sleep logs and wrist-activity monitors, Lauderdale also discovered that people sleep less than they realize: although participants reported averaging nearly seven hours per night, measured sleep was only about six.

So, do rich people worry less? Are they more exhausted by the end of the day? Do they have more comfortable beds? Or do they have better sleeping conditions in their bedrooms, e.g., darkness and silence, with no TV or other people talking?
(Hat-tip: Jonah)

When Should Schools Start in the morning?

When Should Schools Start in the morning?The fourth part of a four-part series on the topic, this one from April 02, 2006….

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More on sleep in adolescents

More on sleep in adolescentsThis is the third part of the series on the topic, from April 01, 2006…

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ClockNews – Adolescent Sleep

ClockNews - Adolescent Sleep
Here is the second post on the topic, from March 28, 2006. A couple of links are broken due to medieval understanding of permalinks by newspapers, but you will not miss too much, I hope….

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Sleep Schedules in Adolescents

Blogging on Peer-Reviewed Research

Sleep Schedules in AdolescentsEarlier this year, during the National Sleep Awareness Week, I wrote a series of posts about the changes in sleep schedules in adolescents. Over the next 3-4 hours, I will repost them all, starting with this one from March 26, 2006. Also check my more recent posts on the subject here and here…

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Adolescent Sleep Schedule

This kind of ignorant bleating makes me froth at the mouth every time – I guess it is because this is my own blogging “turf”.
One of the recurring themes of my blog is the disdain I have for people who equate sleep with laziness out of their Puritan core of understanding of the world, their “work ethic” which is a smokescreen for power-play, their vicious disrespect for everyone who is not like them, and the nasty feeling of superiority they have towards the teenagers just because they are older, bigger, stronger and more powerful than the kids. Not to forget the idiotic notions that kids need to be “hardened”, or that, just because they managed to survive some hardships when they were teens, all the future generations have to be sentenced to the same types of hardships, just to make it even. This is bullying behavior, and disregarding and/or twisting science in the search for personal triumphalism irks me to no end.

I hated getting up early, too. I still hate it, and I’m so far beyond growth hormones that I don’t even remember how they felt. But I do remember that in middle and high school, I dragged myself out of the house at 5 a.m. every day of the week to deliver papers before I caught the 6:45 a.m. bus to school. I never fell asleep in class. Neither did anybody else. And something caused me to grow 6 inches and add 35 pounds between sophomore and junior year. At the end of that kind of day, complete with cross-country, basketball or track, I had no trouble falling asleep at 10 p.m.

He said that he grew up in height and weight when he was in high school. Who knows how much more he would have grown if he was not so sleep deprived (if his self-congatulatory stories are to be believed and he did not slack off every chance he had). Perhaps he would not grow up to be so grouchy and mean-spirited if he had a more normal adolescence.
I don’t know where he got the idea that growth hormone is a cause of the phase-delay of circadian rhythms in adolescence. It could be, but it is unlikely – we just don’t know yet. But, if a hormone is a cause, than it is much more likely to be sex steroids. Perhaps his sleep-deprived and testosterone-deprived youth turned him into a sissy with male anxiety he channels into lashing at those weaker than him?

In previous centuries, adolescents in an agrarian society got up at 4:30 or 5 a.m. with their parents to milk the cows or do any other of a long list of chores. Did growth hormones pass them by? Where were the “studies” that showed they really needed to go to bed after midnight and sleep until 10? And why weren’t their parents all being reported to the DSS? Oh, that’s right, there was no DSS. How did that generation survive?

He assumes that in times before electricity, teenagers used to wake up and fall asleep at the same time adults did. Well, they did not. Studies of sleep patterns in primitive tribes show that adolescents are the last ones to wake up (and nobody bashes them for it – it is the New Primitives with access to media that do that) and the last ones to fall asleep – they serve as first-shift sentries during the night watch.

Even in this, the 21st century, kids who enter the military at 17 find that they can fall asleep easily at 9:30 or 10, because they know they’re going to be getting up at 4:30 or 5. Apparently the Army hasn’t read the study on circadian rhythms.

Actually, the military being the most worried by this problem is funding a lot of research on circadian rhythms and sleep and has been for decades. Because they know, first hand, how big a problem it is and that yelling sargeants do not make alert soldiers.

Kids, if you need more sleep, my study shows there’s a simple way to get it. Turn off – I mean “power down” – the cell phone, the iPod and the computer sometime before 11 p.m. Turn off the TV. Turn off the light. Lie down in bed and close your eyes.

…and sit in the dark for the next four hours, heh?
This being the beginning of the school year, I can expect to see more of such nonsense printed in the MSM and on blogs soon, so I may repost (tomorrow) some of the stuff I have already written against the societal equation of sleep with laziness in general, as well as specifically concerning adolescents (see this, this, this, this and this, for instance).
What especially drives me crazy is that so many teachers, people who work with adolescents every day, succumb to this indulgence in personal power over the children. It is easier to get into a self-righteous ‘high’ than to study the science and do something about the problem. It is easier to blame the kids than to admit personal impotence and try to do something about it by studying the issue.
I am also currently reading a very good National Academies Press book on the topic of sleep in teenagers which I intend to review soon, as well as use as a source for future rants on the topic.
Addendum: Alon Levy extends this discussion to the general issue of ageism as a conservative way to supress change by supressing the habringers of change – the next generation. Excellent read.
I’d like to go in a slightly different direction – the issue of Moral Order (scroll down to the “Adults Over Children” subheading). Of course, adults have moral authority over children. But what it means, i.e., how is this phrase understood and put to practice, differs between authoritarian/conservative and authoritative/liberal worldviews.
A conservative thinks about his child: “I am good and you are bad. I will beat the sh**t out of you for every little transgression and I hope that will teach you well. Learn to love the rod, because the discipline I am giving out today will turn into your self-discipline later. Once you are 18, get the hell out of my house – by that time you should be as moral as I am now.”
That is the recipe for the development of the External Locus of Moral Authority.
A liberal thinks about his child: “I am older, thus more educated, experienced and mature than you are. You are a good child and have a potential to become a deeply moral person. I am here to help you and guide you in solving day-to-day moral dilemmas so, by the time you are an adult, you will naturally strive to do good and behave ethically.”
That is the recipe for the development of the Internal Locus of Moral Authority.

It’s not just the amount of rest, but also the timing of rest

Do pilots get enough rest?:

The federal rules on pilot duty hours and rest periods aren’t the most comprehensible of reads.
One rule allows airlines to schedule pilots to fly for eight hours or less during a 24-hour period without a “rest period during those eight hours.” Another gives pilots who fly for more than eight hours in a 24-hour stretch a break of at least twice the number of hours flown, either “at or before the end of” the eight hours. Pilots who fly more than eight hours during a 24-hour period must receive 18 hours of rest before being assigned any other duties.
“Those rules underwent a modest updating in 1988,” Mazor said. “Then there was a proposal 10 years ago that was far from satisfactory to begin with, and we haven’t even gotten that.”
Mark Rosekind, a psychologist and president of Alertness Solutions in Cupertino, Calif., took part in that 1995 effort to rewrite the FAA flight crew duty and rest rules. At the time, he was a principal investigator with NASA’s Fatigue Countermeasures Program. Today, in addition to running his consulting company, he teaches a course on sleep, fatigue and circadian factors – the internal “clock” that affects numerous body functions – for the NTSB Academy in Ashburn, Va.
“Current FAA regulations were written in 1937 and have not been rewritten in any dramatic way since,” Rosekind said. “In 1937, jets didn’t exist. Today we have airplanes that have more range, travel into more time zones and do more short-haul routes. The regulations don’t reflect the industry today or changes in the science of sleep and circadian rhythms in 50 years.”
The FAA’s 1995 proposal called for a decrease in consecutive duty hours – which includes duties on the ground – from 16 to 14 hours, but an increase in maximum flying time to 10 hours during that 14-hour span. An FAA spokeswoman said the proposed rules drew more than 2,000 comments, mostly in opposition.

Sleep in old age

This is a good article about changes in sleep patterns that occur with old age.

Happy that the Common Ancestor is Common

As we age, our sleep gets less well consolidated: we take more naps during the day and wake up more oftenduring the night. This happens to other mammals as their age. Now we know that it also happens in Drosophila:

“As humans age, so I’m told, they tend not to sleep as well. There are all sorts of reasons — aches and pains, worries about work and lifelong accumulations of sins that pretty much rule out the sweet sleep of innocence.
But what about fruit flies? Not as a cause of insomnia. What about the problems fruit flies have sleeping?
Yes, Drosophila melanogaster also suffer sleep disruption when they get older. And a report on the troubled sleep of drosophila is being published online this week in The Proceedings of the National Academy of Sciences.
This is the kind of science that makes you wonder.
For instance, are the male flies getting up to go to the bathroom threetimes a night? Are the female flies complaining about hot flashes? Of course not. Fruit flies don’t have bathrooms.
Or you might wonder what troubles are keeping the flies up. They don’t have to worry about family values, illegal immigration or debt. They don’t have families or money.
And given the ubiquity of fruit and of scientific research, I’m guessing drosophila, bless their little genomes, must benefit from something close to full employment.”

But that is just the impetus for James Gorman to wonder why so many people deny evolution and why don’t other, like he does, enjoy the wonder of being related to every living organism on this planet:

“What I wonder is why people waste time worrying about whether we evolved from animals. But they do. A disconcerting number of North Americans doubt the fact of evolution. The U.S. seems almost evenly divided on the matter, says a recent report in Science.
Some of the worriers concentrate on apelike ancestors, showing a lack of vision.
There are stranger connections to agonize over, like drosophila and beyond. We share sleep problems with fruit flies. We have a huge amount of DNA in common with yeast.
Those are our distant cousins we consume in leavened bread, our fellow multi-celled organisms undergoing dreadful experiments in the drosophila lab. For instance, scientists have heated up the ambient temperature in fruit flies’ environment to see what happens. At 64 degrees Fahrenheit they live twice as long as at 84 degrees. Live hot, die young.
What does that mean for us?
We really do share a lot with drosophila. Fruit flies have sleep-wake cycles that become fragmented as they age, suffering a “loss of sleep consolidation, namely increased daytime sleep and increased night-time wakefulness in the elderly,” as Kyunghee Koh at the Howard Hughes Medical Institute and three colleagues describe it.
Sound familiar?Some of the same genes related to circadian rhythms occur in humans and in flies. Mutations in some of these shared clock genes can cause sleep disorders in people.
We also share genes related to learning and alcohol sensitivity. But even these commonalities are not worth worrying about. The genes are just details. We have the same basic cell machinery — DNA, for example — with everything living.
The bacteria in my gut accounts for more genes than I have in my chromosomes. We not only have a lot in common with microbes, in a way that is only beginning to be understood, we are microbes.
This is fine with me. I’m delighted to be related to flies, yeast, frogs, chimps and blue-green algae.
I find the serenity of algae restful and the ambition of yeast admirable.
Frogs are great jumpers. Chimps have hands at the end of their feet, sort of.
And fruit flies, well, I never met a fruit fly that I was ashamed to share genes with, and I certainly can’t say that about human beings.”

Wonderfully put. I just had to go over what is appropriate and save all those words here and not let them dissappear into the Black Hole of newspaper archives. Thank you, Mr Gorman.

Reading Recommendations: Books about Clocks and Sleep

Reading Recommendations: Books about Clocks and SleepThis list, written on December 17, 2005, is still quite up-to-date. There are also some more specialized books which are expensive, and many of those I’d like to have one day, but I cannot afford them (though I have placed a couple of them on my wish list, just in case I see a cheap copy come up for sale):

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Why hibernating animals occasionally wake up?

One of the several hypotheses floating around over the past several years to explain the phenomenon of repeated wake-up events in hibernating animals although such events are very energy-draining, is the notion that the immune system needs to be rewarmed in order to fend off any potential bacterial invasions that may have occured while the animal was hibernating:

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Watch out for the Big Trucks….

Many Commercial Drivers Have Impaired Performance Due To Lack Of Sleep

Truck drivers who routinely get too little sleep or suffer from sleep apnea show signs of fatigue and impaired performance that can make them a hazard on the road, according to a major new study by researchers at the University of Pennsylvania School of Medicine. The study results are published in the August 15th issue of the American Journal of Respiratory and Critical Care Medicine.

Wearing blue-blocking eyeglasses a few hours before bedtime resets the internal clocks to an earlier hour.

This is an interesting idea:

A novel way to advance the circadian cycle has been proposed as a way to solve the problem associated with the early starting times of middle and high schools. It has been recognized for some time that teen age students do not really wake up until well past the time they physically arrive at school. Researchers at Brown University have found that the student’s blood contains large amounts of the sleep hormone, melatonin. Researchers at the Lighting Innovations Institute of John Carroll University are seeking funding to carry out a study to find out if their method of advancing the melatonin cycle will help.
It is well known that exposing the eyes to light during the evening delays the start of the flow of melatonin until after the person has gone into the darkness of the bedroom. Because the students like to stay up late working on their computers or watching television, their melatonin cycle is delayed. This means that in the morning, the cycle doesn’t end until well after they are in school.
Five years ago it was discovered that not all light causes suppression of melatonin, only blue light. This means that wearing glasses that block blue light is the same as being in darkness as far as melatonin production is concerned. Putting on blue blocking glasses at 9:00 P.M. will move the circadian cycle forward in time so that the melatonin flow is over before the student gets to school.
The blue blocking glasses have been tested as a means to help people with sleeping problems. Putting on the glasses a few hours before bedtime allows melatonin to be present at the time people go to bed. This avoids the delay in falling asleep experienced by many people. Using the glasses also has been reported to help people sleep more soundly.
As a bonus, having melatonin present for a longer time may also reduce the risk of cancer. Melatonin is known to fight cancer in at least three ways. It is a powerful antioxidant, counteracting the damaging effects of free radicals produced by radiation and chemical pollutants. Melatonin also blunts the cancer-promoting nature of estrogen, and it interferes with the metabolism of materials that cancer cells require as food
Wearing the glasses in the late evening results in getting close to the conditions of light and dark experienced before the invention of artificial lighting. Glasses that block the damaging blue light are available at a web site of a spin-off company formed by the John Carroll researchers, Filters for TV and computer screens as well as safe light bulbs are also available.
The John Carroll University researchers are seeking funding to test the glasses on high schools students to see if moving their circadian cycle forward in time will result in better academic performance in early morning classes.

Well, they are asking funding for research. The underlying science exists, so this is not total hogwash. And they are upfront about the business opportunities for themselves, selling the glasses already even before they did the research.

Recommended reading

Today’s New York Times has a good article about jet-lag: The Science of Zzzzz’s. I am glad to hear that JetBlue is using scientific advice in helping their pilots be fresh and alert, especially now that JetBlue has started flying from RDU.

What happens in bed, stays in bed

Men’s sleep apnea found alongside erectile problems:

Men who are sound sleepers have better sex lives.
A study published in a recent edition of Urology says men who suffer from sleep apnea syndrome also suffer a high rate of erectile dysfunction.
One theory, Dr. Atwood said, suggests that sleep apnea disrupts rapid-eye-movement or REM sleep — a time when men routinely experience erections. Decreased REM sleep means fewer REM erections.
The possibility exists, he said, that REM erections are a necessary process for men to maintain healthy sexual function.

(Hat-tip: Insulin Resistance)

Sleep changes in aging

Sawing The ZZZZZs: Getting Old Needn’t Keep You Awake, Geriatricians Say:

“Patients must be educated on normal sleep-related changes but also made aware that sleep problems are not a part of normal aging.”

Again we have the problem with the use of the word “normal”! Fragmentation of sleep in old age is “normal” in a sense that it happens to most people and most other mammals. Just because it is unpleasant and potentially bad for one’s health does not make it not normal. Yet, just like we treat bad eyeseight with glasses, we can alleviate sleep problems in the elderly with a variety of strategies outlined in this article. Doing something “artifical” about something that is “normal” can make the quality of life be more “normal”.

Sleep in American Social Life

Found on the Talk About Sleep forums:

We here at Talk About Sleep have recently learned of a very interesting study of sleep and sleep disorders being conducted by a Ph.D. student at the University of Minnesota. Matthew Wolf-Meyer is a medical anthropologist and is interested in hearing about your personal experiences as a sleep disorder sufferer, as well as the experiences of your family members.
From what we understand, this is the first social study of sleep disorders and their impacts on the lives of patients and their families. This study could have positive consequences for school and work, so participating could be very important in helping change the social ramifications of sleep disorders.

You can read more about the project here and volunteer to participate here:

The purpose of this study is to examine the ways in which ideas about everyday life in American society are shaped by and shape ideas about sleep. In other words, how do dominant ideas about proper times of sleep shape ideas about proper times for school, work, and family life? How do these ideas impact people with sleep disorders and their friends and loved ones? Are there better ways to organize work, school, and family life so as to minimize interference with the need for sleep?

(Hat-tip: NBM – the Night Owl)