Recent quotes:

Napping and teenage learning

Routine nappers, who napped five to seven days in a week, had sustained attention, better nonverbal reasoning ability and spatial memory. How long to nap is also an important question? The sweet spot is between 30 to 60 minutes. A nap longer than one hour interferes with circadian rhythm. Participants who slept between 30 to 60 minutes produced better accuracy in attention tasks as well as faster speed. She recommends not to nap after 4 p.m., nor over-nap. Researchers were surprised to find a positive relationship between midday napping and nighttime sleep, which is different than the literature. Habitual nappers (who napped more often) tended to have a better nighttime sleep. “That’s different than the findings in the United States, where napping may serve as a function to replace sleep lost from the previous night. Consequently, that may interfere with the following night’s sleep,” Ji said. “In China, a midday nap is considered a healthy lifestyle. Routine nappers are more likely to experience healthy nighttime sleep. So routine nappers are essentially trained to sleep well and sleep more at night.”

Morning sun 99.9% correlates with improved sleep

The Pittsburgh Sleep Quality Index, the Demographic Data Form, and the Follow-up Form for Elderly were used for data collection, whereas the Pittsburgh Sleep Quality Index was used for sample selection. It was found that exposure to direct sunlight between 8 AM and 10 AM for 5 days seems to be effective in increasing the global sleep quality score (P < .001).

How REM and non-REM sleep may work together to help us solve problems -- ScienceDaily

Suppose I give you a creativity puzzle where you have all the information you need to solve it, but you can't, because you're stuck," says first author Penny Lewis, a professor at the Cardiff University School of Psychology. "You could think of that as you've got all the memories that you need already, but you need to restructure them -- make links between memories that you weren't linking, integrate things that you weren't integrating." Studies show that this kind of restructuring often happens while we are asleep, so Lewis and her co-authors drew on that literature, as well as physiological and behavioral data, to create a model of what might be happening during each stage. Their model proposes that non-REM sleep helps us organize information into useful categories, whereas REM helps us see beyond those categories to discover unexpected connections.

New findings explain how melatonin promotes sleep: Discovery may lead to new therapy for insomnia -- ScienceDaily

The experiments singled out one receptor, MT1, as the mechanism via which melatonin acts to inhibit the specific orexin neurons that wake you up. This discovery could help lead to medications that target only the MT1 receptor instead of multiple receptors, which could lead to fewer side effects for those who take sleep-promoting drugs. "Melatonin has been used as a sleep drug for many years, but people didn't know how it worked," Thakkar said. "Our research suggests that if you target the melatonin MT1 receptor, you will get the most sleep with minimal side effects."

The Science of Sleep: Dreaming, Depression, and How REM Sleep Regulates Negative Emotions – Brain Pickings

The more severe the depression, the earlier the first REM begins. Sometimes it starts as early as 45 minutes into sleep. That means these sleepers’ first cycle of NREM sleep amounts to about half the usual length of time. This early REM displaces the initial deep sleep, which is not fully recovered later in the night. This displacement of the first deep sleep is accompanied by an absence of the usual large outflow of growth hormone. The timing of the greatest release of human growth hormone (HGH) is in the first deep sleep cycle. The depressed have very little SWS [slow-wave sleep, Stages 3 and 4 of the sleep cycle] and no big pulse of HGH; and in addition to growth, HGH is related to physical repair. If we do not get enough deep sleep, our bodies take longer to heal and grow. The absence of the large spurt of HGH during the first deep sleep continues in many depressed patients even when they are no longer depressed (in remission). The first REM sleep period not only begins too early in the night in people who are clinically depressed, it is also often abnormally long. Instead of the usual 10 minutes or so, this REM may last twice that. The eye movements too are abnormal — either too sparse or too dense. In fact, they are sometimes so frequent that they are called eye movement storms.

Total sleep deprivation increases extracellular serotonin in the rat hippocampus. - PubMed - NCBI

Sleep deprivation exerts antidepressant effects after only one night of deprivation, demonstrating that a rapid antidepressant response is possible. In this report we tested the hypothesis that total sleep deprivation induces an increase in extracellular serotonin (5-HT) levels in the hippocampus, a structure that has been proposed repeatedly to play a role in the pathophysiology of depression. Sleep deprivation was performed using the disk-over-water method. Extracellular levels of 5-HT were determined in 3 h periods with microdialysis and measured by high performance liquid chromatography coupled with electrochemical detection. Sleep deprivation induced an increase in 5-HT levels during the sleep deprivation day. During an additional sleep recovery day, 5-HT remained elevated even though rats displayed normal amounts of sleep. Stimulus control rats, which had been allowed to sleep, did not experience a significant increased in 5-HT levels, though they were exposed to a stressful situation similar to slee-deprived rats. These results are consistent with a role of 5-HT in the antidepressant effects of sleep deprivation.

One Sleepless Night Increases Dopamine in the Human Brain

“This is the first time that a study provides evidence that in the human brain, dopamine is involved in the adaptations that result from sleep deprivation,” said Nora Volkow, MD, director of the National Institute on Drug Abuse, who led the study. Volkow and colleagues found that in healthy participants, sleep deprivation increased dopamine in two brain structures: the striatum, which is involved in motivation and reward, and the thalamus, which is involved in alertness. The researchers also found that the amount of dopamine in the brain correlated with feelings of fatigue and impaired performance on cognitive tasks. “These findings suggest dopamine may increase after sleep deprivation as a compensatory response to the effects of increased sleep drive in the brain,” said David Dinges, PhD, at the University of Pennsylvania School of Medicine, an expert unaffiliated with the study. “The extent to which this occurs may differentiate how vulnerable people are to the neurobehavioral effects of sleep loss,” Dinges said.

The link between circadian rhythms and aging: Gene associated with longevity also regulates the body's circadian clock -- ScienceDaily

Last year, Guarente found that a robust circadian period correlated with longer lifespan in mice. That got him wondering what role SIRT1, which has been shown to prolong lifespan in many animals, might play in that phenomenon. SIRT1, which Guarente first linked with aging more than 15 years ago, is a master regulator of cell responses to stress, coordinating a variety of hormone networks, proteins and genes to help keep cells alive and healthy.

Visualizing assemblies of the proteins that direct cyanobacterial circadian rhythms

KaiB, though, flips between two different shapes, and is only active when it's in an unstable shape—a situation that until now made crystallization impossible. "We mutated KaiB so that it stayed in its active shape, and when we added KaiA and KaiC they arranged themselves around it as they do at night," LiWang said. "We found the secret sauce that allows us to figure out how the springs and gears go together." They were amazed that they obtained crystals within a day of combining the proteins. They also solved an NMR structure of a complex between the active form of KaiB and the domain of a protein (CikA) that transmits signals to regulate gene expression in cyanobacteria. "It's really remarkable that the cyanobacterial clock is so dependent on this rare state of KaiB," Partch said. "The mechanistic information we're getting out of these structures is allowing us to piece together how the clock manages to keep 24-hour time. We're now looking for similar clues in other circadian timekeeping systems, including our own."

Sleep Shrinks the Brain--and That's a Good Thing - Scientific American

Cirelli said that one interesting finding was that this pruning occurred in about 80 percent of the synapses but spared the largest ones. These larger synapses may be associated with the most stable and important memories, connections the brain does not want to lose, the researchers speculated. Yet, the way in which the brain decides what synaptic connections to prune is another mystery to explore, Cirelli said. "It is critical to have pruning back at night, so that the huge amount of information encoded by temporary synapses during the day won't overwhelm the brain," said Foster. "Pruning ensures that only the most important information is retained."

Insomnia and depression: Japanese hospital workers questionnaire survey : Open Medicine

Chronic insomnia is the one of the factors influencing the development of mental illness. In this survey, we tried to clarify the relationship between chronic insomnia and various factors. Although there is no certainty about other possible independent variables, multiple regression analyses suggested that chronic insomnia is an important factor for depression. Koyama et al. found that subjects who suffered from severe sleeping disorders, not just during depression, tended to have decreased blood flow in the frontal lobe of the brain [2]. When SIGH-D was used to evaluate sleeping disorders, an IS of 3 or higher showed that its severity and the reduced blood flow in the frontal lobe are significantly correlated. Based on this biological finding, preliminary research was conducted with 108 working participants, which included healthy participants and patients with mild to moderate depressive episodes. The result showed that the IS was significantly correlated with the severity of depression, subjective fatigue, sadness, and suicidal thoughts. Thus, an IS evaluation has the possibility of identifying depression based on a questionnaire survey related to direct mood changes [3]. There have been robust findings concerning the biology underlying the close relationship between sleep disorders and depression. For example, Buckley has found that a protracted sleep disorder, not depression, induces hyperactivity of the HPA (hypothalamic-pituitary-adrenal axis) system [14]. Furthermore, exposure to extreme stress causes the excessive secretion of corticotropin releasing hormone (CRH) —a cerebral mechanism for stress adaptation. This release of CRH inhibits the activities of the serotonin pathway in the nervous system that extends from the dorsal raphe nucleus to the prefrontal area via the gamma-aminobutyric acid (GABA) system [15]. It is also known that CRH has a stimulant effect [14]. Therefore, it is inferred that a substantive lack of sleep will lead to a sustained activation of the HPA system once again, thus establishing a vicious cycle. On the other hand, the decline in frontal lobe function due to depression has been established by several earlier studies, including those that used functional brain imaging [15,16,17,18]. The protraction of a sleep disorder activating the HPA system and inhibiting the serotonin nervous system in the frontal lobe is believed to elicit a clinical condition similar to depression. Furthermore, the finding that the hyperactivity of the HPA system increases cortisol secretion, which inhibits the HPA system and damages hippocampal cells, further strengthens the suggested relationship between sleep disorders and depression. This biological finding strengthens the theory that a lack of sleep due to insomnia, exposure to stress, and overwork, leads to depression because of the accumulation of mental fatigue.

Amid ADHD spike, doctors urge closer look at sleep issues -- ScienceDaily

D-diagnosed children whose behavior only improves after better sleep quality and duration. Occasionally, he has found that ADHD medications are the root of the sleep issues.

irregular sleep screws you

the researchers were able to assess the timing of circadian rhythms. On average, melatonin was released 2.6 hours later in students with the most irregular sleep patterns, compared with students with more regular sleep patterns.

Amber-tinted glasses may provide relief for insomnia -- ScienceDaily

To test their theory, the researchers recruited 14 individuals with an insomnia diagnosis to take part in a small study. For seven consecutive nights, participants wore wrap-around frames with amber-tinted lenses that blocked blue light or with clear placebo lenses for two hours before bedtime. Four weeks later, participants repeated the protocol with the other set of glasses. The researchers found that participants got around 30 minutes extra sleep when they wore the amber lenses compared to the clear lenses. In self-reported sleep surveys, participants also reported greater duration, quality, and soundness of sleep, and an overall reduction in insomnia severity.

Antidepressants and the Placebo Effect

Yet this 11% figure may overestimate the number of people who benefit from antidepressants. Antidepressants are also prescribed to people who do not qualify for the diagnosis of major depression. My neighbor’s pet dog died; his physician prescribed an antidepressant. A friend in the US was diagnosed with lumbar muscle spasms and was prescribed an antidepressant. I have lost count of the number of people who have told me they were prescribed antidepressants when complaining of insomnia – even though insomnia is a frequently reported side effect of antidepressants. About 20% of patients suffering from insomnia in the United States are given antidepressants as a treatment by their primary care physicians (Simon & VonKorff, 1997), despite the fact that “the popularity of antidepressants in the treatment of insomnia is not supported by a large amount of convincing data, but rather by opinions and beliefs of the prescribing physicians” (Wiegand, 2008, p. 2411).

New insights into how sleep helps the brain to reorganize itself -- ScienceDaily

Dr Julie Seibt, Lecturer in Sleep and Plasticity at the University of Surrey and lead author of the study, said: "Our brains are amazing and fascinating organs -- they have the ability to change and adapt based on our experiences. It is becoming increasingly clear that sleep plays an important role in these adaptive changes. Our study tells us that a large proportion of these changes may occur during very short and repetitive brain waves called spindles. "Sleep spindles have been associated with memory formation in humans for quite some time but nobody knew what they were actually doing in the brain. Now we know that during spindles, specific pathways are activated in dendrites, maybe allowing our memories to be reinforced during sleep. "In the near future, techniques that allow brain stimulation, such as transcranial magnetic stimulation (TMS), could be used to stimulate dendrites with the same frequency range as spindles. This could lead to enhance cognitive functions in patients with learning and memory disorders, such as dementia."

Lack of sleep could contribute to mental health problems, researchers reveal | Society | The Guardian

After taking into account effects not linked to treatment – as deduced from the no-treatment group – insomnia in the CBT group was found to have fallen by almost half 10 weeks into the study, while both anxiety and depression dropped by a fifth, and paranoia and hallucinations fell by 25% and 30% respectively. “Having insomnia doubles your chances of developing depression and we now know that if you treat the insomnia it reduces depression,” said Freeman.

Is ADHD really a sleep problem? -- ScienceDaily

"There is extensive research showing that people with ADHD also tend to exhibit sleep problems. What we are doing here is taking this association to the next logical step: pulling all the work together leads us to say that, based on existing evidence, it looks very much like ADHD and circadian problems are intertwined in the majority of patients. We believe this because the day and night rhythm is disturbed, the timing of several physical processes is disturbed, not only of sleep, but also of temperature, movement patterns, timing of meals, and so on. If you review the evidence, it looks more and more like ADHD and sleeplessness are 2 sides of the same physiological and mental coin."

The role of sleep in bipolar disorder | NSS

A convergence of evidence suggests that sleep problems in bipolar disorder result from dysregulation across both process C and process S systems. Biomarkers of depressive episodes include heightened fragmentation of rapid eye movement (REM) sleep, reduced REM latency, increased REM density, and a greater percentage of awakenings, while biomarkers of manic episodes include reduced REM latency, greater percentage of stage I sleep, increased REM density, discontinuous sleep patterns, shortened total sleep time, and a greater time awake in bed. These findings highlight the importance of targeting novel treatments for sleep disturbance in bipolar disorder.

Sleep, dopamine and memory

The study shows that increasing sleep, with either a sleep-promoting drug or by genetic stimulation of the neural sleep circuit, decreases signaling activity by dopamine, while at the same time enhancing memory retention. Conversely, increasing arousal stimulates dopamine signaling and accelerates forgetting. This signal activity isn’t constant but is tied directly to the animal’s arousal level. “Our findings add compelling evidence to support the model that sleep reduces the forgetting signal in the brain, thereby keeping memories intact,” Davis said. “As sleep progresses to deeper levels, dopamine neurons become less reactive to stimuli and this leads to more stable memories.

Loneliness in young adults linked to poor sleep quality -- ScienceDaily

Loneliness is defined by researchers as a distressing feeling that people experience when they perceive their social relationships to be inadequate. This is distinct from the concept of social isolation, as people can be socially isolated without feeling lonely, or feel lonely despite being surrounded by many people. While the effect of being lonely is well documented among the elderly, it is a common problem for young people too -- the Mental Health Foundation reports that loneliness is most frequent between the ages of 18-34. Despite this, little is known about health problems that are associated with loneliness among young adults, or the impact on sleep.

FitBit's new sleep tracker is pretty darn cool

imagine what we’ll learn as warehouses worth of enhanced sleep data like get integrated into drug trials, therapy, physical exams, coaching, research and even education.

ADjusting the body's clock with light to counter depression

Researchers have developed a limited form of sleep deprivation that is euphemistically called wake therapy. It has been shown to have sustained antidepressant benefit in patients with bipolar disorder and major depression. The idea is to get up for the day halfway through the usual sleep period, which shifts the circadian clock to an earlier time. It’s thought that this works by realigning the sleep cycle with other circadian rhythms, like changes in levels of body temperature and the stress hormone cortisol, that are also out of sync with each other in depression. Studies show that it is possible to make wake therapy even more powerful by incorporating two additional interventions: early morning light therapy and what’s called sleep phase advance, in which the patient goes to bed about five to six hours earlier than usual and sleeps for about seven hours. This combination of treatments is called triple chronotherapy, and the typical course involves one night of complete sleep deprivation followed by three nights of phase-advanced sleep and early morning light. In one study of 60 hospitalized patients with bipolar depression who were taking antidepressants or lithium, 70 percent of those who did not have a history of drug resistance improved rapidly with sleep deprivation and early morning light, and 57 percent remained well after nine months. Encouragingly, 44 percent of patients who had failed to respond to at least one trial of anti-depressants also improved.

Gene mutation helps explain night owl behavior

Night owls are often diagnosed at sleep clinics with delayed sleep phase disorder (DSPD). This study is the first to implicate a gene mutation in the development of DSPD, which affects up to 10% of the public, according to clinical studies. People with DSPD often struggle to fall asleep at night, and sometimes sleep comes so late that it fractures into a series of long naps. DSPD and other sleep disorders are associated with anxiety, depression, cardiovascular disease, and diabetes. People with DSPD also have trouble conforming to societal expectations and morning work schedules. "It's as if these people have perpetual jet lag, moving eastward every day," says Young. "In the morning, they're not ready for the next day to arrive." Patke is a night owl and usually works late into the night. She, however, does not carry the CRY1 variant. Not all cases of DSPD are attributable to this gene mutation. However, Young and Patke found it in 1 in 75 of individuals of non-Finnish, European ancestry in a gene database search. "Our variant has an effect on a large fraction of the population," she says. Young, who has studied the genes involved in the circadian clock of the fruit fly, connected with clinical researchers at the Weill Cornell Medical College to understand the molecular underpinnings of human sleep disorders. By studying the skin cells of people with DSPD, he and Patke discovered a mutation in CRY1, which helps drive the circadian clock. The circadian clock is a fundamental element of life on Earth and has remained more or less the same, genetically, throughout the evolution of animals. "It's basically the same clock from flies to humans," Young says. Normally the clock begins its cycle by building up proteins, call activators, in a cell. These activators produce their own inhibitors that, over time, cause the activators to lose their potency. When all the activators in the cell have been silenced, inhibitors are no longer produced and eventually degrade. Once they've all gone, the potency of the activators surges, and the cycle begins again. The CRY1 protein is one of the clock's inhibitors. The mutation Young and Patke found is a single-point mutation in the CRY1 gene, meaning just one letter in its genetic instructions is incorrect. Yet this change causes a chunk of the gene's resulting protein to be missing. That alteration causes the inhibitor to be overly active, prolonging the time that the activators are suppressed and stretching the daily cycle by half an hour or more. In addition to their initial study of a multigenerational family in the U.S., Young and Patke collaborated with clinical researchers at Bilkent University to analyze the sleep patterns of six families of Turkish individuals, 39 carriers of the CRY1 variant and 31 non-carriers. The carriers had delayed sleep onset times and some had fractured, irregular sleep patterns. The mid-point of sleep for non-carriers was about 4 a. m. But for carriers, the mid-point was shifted to 6-8 a.m. Because the mutation does not disable the protein, it can have an effect on individuals whether they carry one or two copies of the gene. Of the 39 Turkish carriers studied, 8 had inherited the mutation from both parents, and 31 had inherited only one copy of the mutation. The circadian clock responds to external environmental cues, so it is possible for people to manage the effects of the mutation on sleep. For instance, one carrier in the study reported maintaining a sleep routine through self-enforced regular sleep and wake times and exposure to bright light during the day. "An external cycle and good sleep hygiene can help force a slow-running clock to accommodate a 24-hour day," says Patke. "We just have to work harder at it."

REM versus deep sleep

I was just going to comment that there's also evidence that suggest that deeper sleep, that what we call slow-wave sleep, non-REM sleep, might be more involved in sort of strengthening memories in a way that they're for REM. So for example, if you want to remember someone's name or phone number that might be where that non-REM sleep is valuable. And that REM sleep seems to be more involved in memory processing where you're not trying to exactly remember it in the form that you first saw it but rather to extract meaning from it. So to get patterns or to figure out the rules of something or to extract just to get the sort of the executive summary. But that seems to be more of what REM sleep that's about and that would fit in with the emotional piece too because, of course, if something had happens during the day, you don't simply want to remember it better than next morning. You want to understand it.

REM launders emotion

One of the things that's been emerging over the past five or six years in the literature is that REM sleep seems to serve an almost sort of overnight therapy benefit in terms of our emotional well-being and our mental health. And what's interesting is that REM sleep chemically, in terms of the anuric transmitters that swirl around the brain, REM sleep is perhaps the only time during the 24-hour period where a particular stress neurochemical called norepinephrine or noradrenaline is actually suppressed and it's completely shut down from the brain. And it seems to be that REM sleep is a perfect chemical environment, almost like a therapy session, where you can take emotional events from the prior day and perhaps just smooth the sharp edges off those experiences, and almost like an overnight soothing balm, as it were.