1. Study suggests there are genes that up insomnia risk

    June 25, 2017 by Ashley

    From the Vrije Universiteit Amsterdam press release:

    An international team of researchers has found, for the first time, seven risk genes for insomnia. With this finding the researchers have taken an important step towards the unravelling of the biological mechanisms that cause insomnia. In addition, the finding proves that insomnia is not, as is often claimed, a purely psychological condition. Today, Nature Genetics publishes the results of this research.

    Insomnia is probably the most common health complaint. Even after treatment, poor sleep remains a persistent vulnerability for many people. By having determined the risk genes, professors Danielle Posthuma (VU and VUmc) and Eus Van Someren (Netherlands Institute for Neuroscience, VU and VUmc), the lead researchers of this international project, have come closer to unravelling the biological mechanisms that cause the predisposition for insomnia.

    Hope and recognition for insomniacs

    Professor Van Someren, specialized in sleep and insomnia, believes that the findings are the start of a path towards an understanding of insomnia at the level of communication within and between neurons, and thus towards finding new ways of treatment.

    He also hopes that the findings will help with the recognition of insomnia. “As compared to the severity, prevalence and risks of insomnia, only few studies targeted its causes. Insomnia is all too often dismissed as being ‘all in your head’. Our research brings a new perspective. Insomnia is also in the genes.”

    In a sample of 113,006 individuals, the researchers found 7 genes for insomnia. These genes play a role in the regulation of transcription, the process where DNA is read in order to make an RNA copy of it, and exocytosis, the release of molecules by cells in order to communicate with their environment. One of the identified genes, MEIS1, has previously been related to two other sleep disorders: Periodic Limb Movements of Sleep (PLMS) and Restless Legs Syndrome (RLS). By collaborating with Konrad Oexle and colleagues from the Institute of Neurogenomics at the Helmholtz Zentrum, München, Germany, the researchers could conclude that the genetic variants in the gene seem to contribute to all three disorders. Strikingly, PLMS and RLS are characterized by restless movement and sensation, respectively, whereas insomnia is characterized mainly by a restless stream of consciousness.

    Genetic overlap with other characteristics

    The researchers also found a strong genetic overlap with other traits, such as anxiety disorders, depression and neuroticism, and low subjective wellbeing. “This is an interesting finding, because these characteristics tend to go hand in hand with insomnia. We now know that this is partly due to the shared genetic basis,” says neuroscientist Anke Hammerschlag (VU), PhD student and first author of the study.

    Different genes for men and women

    The researchers also studied whether the same genetic variants were important for men and women. “Part of the genetic variants turned out to be different. This suggests that, for some part, different biological mechanisms may lead to insomnia in men and women,” says professor Posthuma. “We also found a difference between men and women in terms of prevalence: in the sample we studied, including mainly people older than fifty years, 33% of the women reported to suffer from insomnia. For men this was 24%.”

    The risk genes could be tracked down in cohorts with the DNA and diagnoses of many thousands of people. The UK Biobank — a large cohort from England that has DNA available — did not have information as such about the diagnosis of insomnia, but they had asked their participants whether they found it difficult to fall asleep or to have an uninterrupted sleep. By making good use of information from slaapregister.nl (the Dutch Sleep Registry), the UK Biobank was able, for the first time, to determine which of them met the insomnia profile. Linking the knowledge from these two cohorts is what made the difference.


  2. Irregular sleeping patterns linked to poorer academic performance in college students

    June 24, 2017 by Ashley

    From the Brigham and Women’s Hospital press release:

    Previous research has analyzed variations in sleep patterns including number of hours slept, quality of sleep, and sleep-wake times, and found an association with cognitive impairments, health and performance; however, few studies have considered or accurately quantified the effects of regular sleep patterns. In a new study at Brigham and Women’s Hospital, researchers objectively measured sleep and circadian rhythms, and the association to academic performance in college students, finding that irregular patterns of sleep and wakefulness correlated with lower grade point average, delayed sleep/wake timing, and delayed release of the sleep-promoting hormone melatonin. The results are published in Scientific Reports on June 12, 2017.

    Researchers studied 61 full-time undergraduates from Harvard College for 30 days using sleep diaries. They quantified sleep regularity using the sleep regularity index (SRI), a newly devised metric. Researchers examined the relationship between the SRI, sleep duration, distribution of sleep across the day, and academic performance during one semester.

    “Our results indicate that going to sleep and waking up at approximately the same time is as important as the number of hours one sleeps,” stated Andrew J. K. Phillips, PhD, biophysicist at the Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital and lead author on the paper. “Sleep regularity is a potentially important and modifiable factor independent from sleep duration,” Phillips said.

    Students with more regular sleep patterns had better school grades on average. Researchers found no significant difference in average sleep duration between most students with irregular sleep patterns and most regular sleepers.

    “We found that the body clock was shifted nearly three hours later in students with irregular schedules as compared to those who slept at more consistent times each night, stated Charles A. Czeisler, PhD, MD, Director of the Sleep Health Institute at Brigham and Women’s Hospital, and senior author on the paper. “For the students whose sleep and wake times were inconsistent, classes and exams that were scheduled for 9 a.m. were therefore occurring at 6am according to their body clock, at a time when performance is impaired. Ironically, they didn’t save any time because in the end they slept just as much as those on a more regular schedule.”

    By measuring the timing of melatonin release at sleep onset, 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 to students with more regular sleep patterns.

    “Using a mathematical model of the circadian clock, we were able to demonstrate that the difference in circadian timing between students with the most irregular sleep patterns and students with regular sleep patterns was consistent with their different patterns of daily light exposure,” stated Phillips. “In particular, regular sleepers got significantly higher light levels during the daytime, and significantly lower light levels at night than irregular sleepers who slept more during daytime hours and less during nighttime hours.”

    Researchers note that the circadian clock takes time to adjust to schedule changes, and is highly sensitive to patterns of light exposure. Irregular sleepers, who frequently changed the pattern of when they slept and consequently their pattern of light-dark exposure, experienced misalignment between the circadian system and the sleep-wake cycle.

    Researchers conclude that light based interventions, including increased exposure to daytime light and less exposure to electronic light-emitting devices before bedtime, may be effective in improving sleep regularity.


  3. New research identifies a group of neurons that can help us stay awake when it matters

    June 22, 2017 by Ashley

    From the California Institute of Technology press release:

    Caltech researchers have identified a neural circuit in the brain that controls wakefulness. The findings have implications for treating insomnia, oversleeping, and sleep disturbances that accompany other neuropsychiatric disorders, such as depression.

    The work was done in the laboratory of Viviana Gradinaru (BS ’05), assistant professor of biology and biological engineering, Heritage Medical Research Institute Investigator, and director of the Center for Molecular and Cellular Neuroscience of the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech. It appears in the June 8 online edition of the journal Neuron.

    Gradinaru and her team wanted to know: How do we overcome tiredness in the face of a looming deadline or rouse ourselves in the dead of night to feed a crying baby? In other words, in the face of so-called salient stimuli, how do we override the natural drive to sleep?

    “To answer this question, we decided to examine a region of the brain, called the dorsal raphe nucleus, where there are an under-studied group of dopamine neurons called dorsal raphe nucleus neurons, or DRNDA neurons,” says Gradinaru. “People who have damage in this part of their brain have been shown to experience excessive daytime sleepiness, but there was not a good understanding of the exact role of these neurons in the sleep/wake cycle and whether they react to internal or external stimuli to influence arousal.”

    The team studied DRNDA neurons in mice, which are a model organism for studying the human brain. First, the team measured DRNDA activity while the animals encountered salient stimuli, such as the arrival of a potential mating partner, or a sudden unpleasant sensation, or food. The DRNDA neurons were highly active during these events, which led the researchers to theorize that the neurons send signals of salience and arousal, which can then modulate the state of sleep or wakefulness.

    “We then measured DRNDA activity throughout the sleep/wake cycle and found that these neurons are least active when the animal is sleeping and increase in activity as the animal is waking up,” says Ryan Cho, a graduate student and the first author on the paper. “We aimed to discover whether this was just a correlation or if the activity of the neurons was actually causing changes in sleep-wake states.”

    The researchers used a technique called optogenetics to engineer DRNDA cells to be stimulated by light. After stimulating these neurons with light during the time that the animal would normally sleep, Gradinaru and her team found that the mouse woke up from sleep and remained awake. The reverse was true when the activity of DRNDA was chemically silenced — the animal was likely to fall asleep, even in the face of motivationally important stimuli, such as the odor of a predator or a mating partner. This implied that activity of the DRNDA neurons truly governed sleep-wake behaviors.

    Finally, the researchers examined the role of these neurons in awaking due to external stimuli. The neurons’ activity was silenced with optogenetics, and a loud noise was played while the animals were asleep. Whereas control mice often woke up, the mice with blocked DRNDA often ignored the sound and remained asleep.

    “These experiments showed us that DRNDA cells are necessary for full wakefulness in the face of important stimuli in mice,” Gradinaru says. “DRNDA neurons are found analogously in humans, and while they have not been studied in depth, their degeneration has been correlated with excessive daytime sleepiness in patients with neurodegenerative disorders such as multiple systems atrophy and Lewy body dementia. Further work is necessary to establish causation in humans and to test the potential of the DRNDA as a therapeutic target for insomnia or oversleeping, and for sleep disturbances that accompany other psychiatric disorders such as depression, bipolar disorder, and schizophrenia.”


  4. Sleep duration impacts treatment response for depressed patients with insomnia

    June 21, 2017 by Ashley

    From the American Academy of Sleep Medicine press release:

    Preliminary results from a new study show that depressed patients with insomnia who sleep seven or more hours per night are more likely to benefit from cognitive behavioral therapy for insomnia (CBTI) and achieve depression remission.

    Results show that when insomnia and depression co-occur, longer pre-treatment objective sleep duration is predictive of remission of both disorders when patients are given a combination of CBTI for insomnia and antidepressant medication for depression.

    “A seven-hour, objective sleep duration of patients prior to entering treatment increased their chances of achieving both depression and insomnia remission by their treatment endpoints,” said lead author and co-principal investigator Jack D. Edinger, PhD, professor in the Section of Sleep Medicine at National Jewish Health in Denver, Colorado.

    The study involved 104 adults, including 75 women, who enrolled in the Treatment of Insomnia and Depression Study and completed one baseline night of polysomnography. Participants received 16 weeks of anti-depressant medication and were randomly assigned either to CBTI or sham insomnia therapy. The Hamilton Rating Scale for Depression (HAMD-17) and Insomnia Severity Index were administered at baseline and then bi-weekly during treatment to determine depression and insomnia remission.

    The study was part of a larger research project for which Edinger was co-investigator along with co-investigators Daniel Buysse, MD, from the University of Pittsburgh; Andy Krystal, MD, from Duke University and the University of California, San Francisco; and lead principal investigator Rachel Manber, PhD, professor of psychiatry and behavioral sciences at the Stanford University Medical Center.

    “Our findings highlight the importance of adequate objective sleep in the recovery from depression and insomnia,” said Manber. “The data suggest that short sleep duration may be a risk for refractory depression.”

    The research abstract was published recently in an online supplement of the journal Sleep and will be presented Monday, June 5, in Boston at SLEEP 2017, the 31st Annual Meeting of the Associated Professional Sleep Societies LLC (APSS), which is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.


  5. Study suggests short-term sleep loading can improve sports performance

    June 19, 2017 by Ashley

    From the American Academy of Sleep Medicine press release:

    Preliminary results from a new study suggest that short-term sleep extension improves response time and daytime functioning of professional baseball players.

    Results show that after five nights of sleep extension, professional baseball players from an MLB organization demonstrated a 13-percent improvement on a cognitive processing speed test by reacting 122 milliseconds faster. They also responded 66 milliseconds faster on a test of selective attention when confronted with distractors. According to the authors, a fastball takes approximately 400 milliseconds to travel from the pitcher to the hitter, requiring batters to have optimal visual search strategies to distinguish and react to different types of pitches.

    “Our research indicates that short-term sleep extension of one additional hour for five days demonstrated benefits on athletes’ visual search abilities to quickly respond when faced with distractors,” said lead author Cheri D. Mah, MS, research fellow at the University of California San Francisco Human Performance Center.

    The research team led by Mah conducted a randomized, controlled trial during a 4-week training camp. Seventeen professional baseball players from an MLB organization completed a two-day baseline of habitual sleep. Athletes then were randomized to either five nights of sleep extension or five nights of habitual sleep. Pre- and post-cognitive tests included the Digit Symbol Substitution Task (DSST) and an adaptive visual search task. Mood and daytime sleepiness were evaluated with the Profile of Mood States (POMS) and Epworth Sleepiness Scale.

    In the sleep extension group, the objective, estimated sleep duration measured by actigraphy increased by 0.6 hours per night from 6.3 to 6.9 hours. Assessments of fatigue, tension, and daytime sleepiness all decreased by more than one-third after sleep extension.

    “Fatigue over a season can negatively impact performance and possibly pitch recognition,” said Mah. “These findings suggest that short-term sleep loading during periods of high training volumes may be a practical recovery strategy and fatigue countermeasure that has daytime performance benefits.”

    The research abstract was published recently in an online supplement of the journal Sleep and will be presented Monday, June 5, in Boston at SLEEP 2017, the 31st Annual Meeting of the Associated Professional Sleep Societies LLC (APSS), which is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

    In a previous study published in the journal Sleep, Mah found that a 5-7 week sleep extension period was associated with improvements in specific measures of basketball performance among collegiate athletes.


  6. Study links social jet lag to worse mood, poorer health and heart disease

    June 18, 2017 by Ashley

    From the American Academy of Sleep Medicine press release:

    Preliminary results of a new study show that social jet lag has emerged as an important circadian marker for health outcomes.

    Results show that social jet lag, which occurs when you go to bed and wake up later on weekends than during the week, is associated with poorer health, worse mood, and increased sleepiness and fatigue. Each hour of social jet lag also is associated with an 11-percent increase in the likelihood of heart disease. These effects are independent of sleep duration and insomnia symptoms, which are related to both social jet lag and health.

    “These results indicate that sleep regularity, beyond sleep duration alone, plays a significant role in our health,” said lead author Sierra B. Forbush, an undergraduate research assistant in the Sleep and Health Research Program at the University of Arizona in Tucson. “This suggests that a regular sleep schedule may be an effective, relatively simple, and inexpensive preventative treatment for heart disease as well as many other health problems.”

    The research team was led by senior author Michael A. Grandner, PhD, MTR, director of the Sleep and Health Research Program. They utilized data from the community-based Sleep and Healthy Activity, Diet, Environment, and Socialization (SHADES) study, analyzing survey responses from 984 adults between the ages of 22 and 60 years.

    Social jet lag was assessed using the Sleep Timing Questionnaire and was calculated by subtracting weekday from weekend sleep midpoint. Overall health was self-reported using a standardized scale, and survey questions also assessed sleep duration, insomnia, cardiovascular disease, fatigue, and sleepiness.

    The American Academy of Sleep Medicine recommends that adults should sleep 7 or more hours per night on a regular basis to promote optimal health. In addition to adequate duration, healthy sleep requires good quality, appropriate timing and regularity.


  7. Study suggests sleep regularity is important for happiness and well-being of college students

    June 17, 2017 by Ashley

    From the American Academy of Sleep Medicine press release:

    Preliminary results from the “SNAPSHOT study,” an NIH-funded collaborative research project between the Division of Sleep and Circadian Disorders at Brigham and Women’s Hospital, and MIT Media Lab Affective Computing Group, suggest that keeping a regular sleep pattern contributes to the happiness and well-being of college students.

    Results show that higher sleep regularity was significantly related to higher morning and evening happiness, healthiness and calmness during the week. Transitioning from an irregular weekly sleep pattern to a regular pattern also was associated with improved well-being, both during the week of regular sleep and on the day following it.

    “We found that week-long irregular sleep schedules are significantly associated with lower self-reported morning and evening happiness, healthiness, and calmness during the week even after controlling for weekly average sleep duration,” said lead author Akane Sano, PhD, research scientist in the Media Lab Affective Computing Group at the Massachusetts Institute of Technology in Cambridge.

    The analysis involved 204 college students between the ages of 18 and 25 years who participated in a 30-day field study. Sleep timing and duration were monitored using actigraphy, along with daily morning and evening Internet-based diaries. Self-reports of well-being (happiness, healthiness, and calmness) were collected using daily diaries.

    “Irregular sleep-wake schedules are common in our modern society,” said Sano. “Our results indicate the importance of sleep regularity, in addition to sleep duration, and that regular sleep is associated with improved well-being.”

    According to the authors, this study underlines the necessity of considering sleep regularity as an important factor for understanding self-reported well-being.

    The research abstract was published recently in an online supplement of the journal Sleep and will be presented Monday, June 5, in Boston at SLEEP 2017, the 31st Annual Meeting of the Associated Professional Sleep Societies LLC (APSS), which is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.


  8. Study links sleep disturbances to higher incidence of substance use among college athletes

    June 16, 2017 by Ashley

    From the American Academy of Sleep Medicine press release:

    Preliminary results of a new study show that sleep disturbance is strongly related to the use of alcohol, tobacco, and illicit drugs among student athletes in college.

    Results show that student athletes with sleep difficulties were 151 percent more likely to use cigarettes, 36 percent more likely to drink alcohol, and 66 percent more likely to smoke marijuana. Sleep difficulties also predict an increased use of controlled, illegal, and banned substances. For example, student athletes with sleep difficulties were 317 percent more likely to use methamphetamine, 349 percent more likely to use cocaine, and 175 percent more likely to use steroids.

    “The most surprising thing was the consistency with which sleep difficulties among student athletes predict increased use of many substances, including substances that are illegal and banned,” said senior author Michael Grander, PhD, director of the Sleep and Health Research Program at the University of Arizona in Tucson. “Across the board, students with sleep difficulties were more likely to smoke, drink, and use illegal substances.”

    The study involved an analysis of survey data completed from 2011 to 2014 by 8,683 student athletes at U.S. colleges and universities as part of the National College Health Assessment conducted by the American College Health Association. Participants were asked whether, in the past 12 months, “sleep difficulties” had “been traumatic or very difficult for you to handle.” Students also were asked whether they had used a list of specific substances in the past 30 days.

    Regression analyses examined whether use of any of these substances was associated with sleep difficulties, adjusted for age, sex, and survey year. Also, discrepancy between student use and perceived typical use and sleep was examined.

    “Sleep difficulties are quite common among students and especially student athletes,” said lead author Chloe Warlick, research assistant in the Sleep and Health Research Program. “Substance use is also a major public health problem. These results not only underscore the important link between sleep difficulties and substance use, but they show that this relationship is quite strong, even among student athletes.”

    Grandner added that the findings have important implications for both student health and athletic performance.

    “Knowing this association between sleeping difficulty and substance abuse could be beneficial for coaches, physical therapists, and physicians,” he said. “These findings could provide important insight when treating sleep disturbances or attempting to improve athletic performance.”

    The authors concluded that sleep-focused interventions should be evaluated to determine whether they decrease use of psychoactive substances.


  9. Connecting the dots between dreams and brain disease

    June 9, 2017 by Ashley

    From the Canadian Association for Neuroscience press release:

    Dr. John Peever at the University of Toronto has been working to answer one of humanity’s greatest questions: how do we dream? He has found a certain area of the brain is responsible for this phenomenon and that troubles with normal dreaming may be an early warning sign for ailments such as Parkinson’s Disease. His results were presented at the 2017 Canadian Neuroscience Meeting, the annual meeting of the Canadian Association for Neuroscience — Association Canadienne des Neurosciences (CAN-ACN).

    Since the 1960s, the brainstem has been known to be involved in controlling the act of dreaming during Rapid Eye Movement (REM) sleep. Dr. Peever has since found the cells responsible for the dream state, called REM-active neurons. More importantly, the team has learned how to control these cells in rodents and in the process, dreaming. As Peever puts it, “When we switch on these cells, it causes a rapid transition into REM sleep.”

    With this knowledge in hand, his team has examined dreaming dysfunctions such as REM sleep behaviour disorder in humans. Incredibly, the team has unveiled a link to a certain group of neurodegenerative diseases. “We observed that more than 80% of people who suffer from REM sleep disorder eventually develop synucleinopathies, such as Parkinson’s Disease, and Lewy bodies dementia. Our research suggests sleep disorders may be an early warning sign for diseases that may appear some fifteen years later in life.”

    Peever hopes his research may eventually lead to a neuroprotective strategy. “Much like we see in people prone to cancer, diagnosing REM disorders may allow us to provide individuals with preventative actions to keep them healthy long before they develop these more serious neurological conditions.” This goal will take years to develop yet, but could one day help thousands of people live healthier lives long before they need serious medical attention.


  10. Deep sleep maintains the learning efficiency of the brain

    June 5, 2017 by Ashley

    From the University of Zürich press release:

    For the first time, researchers of the University of Zurich and Swiss Federal Institute of Technology in Zurich have demonstrated the causal context of why deep sleep is important to the learning efficiency of the human brain. They have developed a new, non-invasive method for modulating deep sleep in humans in a targeted region of the brain.

    Most people know from their own experience that just a single sleepless night can lead to difficulty in mastering mental tasks the next day. Researchers assume that deep sleep is essential for maintaining the learning efficiency of the human brain in the long term. While we are awake, we constantly receive impressions from our environment, whereby numerous connections between the nerve cells — so-called synapses — are excited and intensified at times. The excitation of the synapses does not normalize again until we fall asleep. Without a recovery phase, many synapses remain maximally excited, which means that changes in the system are no longer possible: Learning efficiency is blocked.

    Causal connection between deep sleep and learning efficiency

    The connection between deep sleep and learning efficiency has long been known and proven. Now, researchers at the University of Zurich (UZH) and the Swiss Federal Institute of Technology (ETH) in Zurich have been able to demonstrate a causal connection within the human brain for the first time. Reto Huber, professor at the University Children’s Hospital Zurich and of Child and Adolescent Psychiatry at UZH, and Nicole Wenderoth, professor in the Department of Health Sciences and Technology at the ETH Zurich, have succeeded in manipulating the deep sleep of test subjects in targeted areas. “We have developed a method that lets us reduce the sleep depth in a certain part of the brain and therefore prove the causal connection between deep sleep and learning efficiency,” says Reto Huber.

    Subjective sleep quality was not impaired

    In the two-part experiment with six women and seven men, the test subjects had to master three different motoric tasks. The concrete assignment was to learn various sequences of finger movements throughout the day. At night, the brain activity of the test subjects during sleep was monitored by EEG. While the test subjects were able to sleep without disturbance after the learning phase on the first day, their sleep was manipulated in a targeted manner on the second day of the experiment — using acoustic stimulation during the deep sleep phase. To do so, the researchers localized precisely that part of the brain responsible for learning the abovementioned finger movements, i.e., for the control of motor skills (motor cortex). The test subjects were not aware of this manipulation; to them, the sleep quality of both experimental phases was comparable on the following day.

    Deep sleep disturbances impair learning efficiency

    In a second step, researchers tested how the manipulation of deep sleep affected the motoric learning tasks on the following day. Here, they observed how the learning and performance curves of the test subjects changed over the course of the experiment. As expected, the participants were particularly able to learn the motoric task well in the morning. As the day went on, however, the rate of mistakes rose. After sleep, the learning efficiency considerably improved again. This was not the case after the night with the manipulated sleep phase. Here, clear performance losses and difficulties in learning the finger movements were revealed. Learning efficiency was similarly as weak as on the evening of the first day of the experiment. Through the manipulation of the motor cortex, the excitability of the corresponding synapses was not reduced during sleep. “In the strongly excited region of the brain, learning efficiency was saturated and could no longer be changed, which inhibited the learning of motor skills,” Nicole Wenderoth explains.

    In a controlled experiment with the same task assignment, researchers manipulated another region of the brain during sleep. In this case, however, this manipulation had no effect on the learning efficiency of the test subjects.

    Use in clinical studies planned

    The newly gained knowledge is an important step in researching human sleep. The objective of the scientists is to use this knowledge in clinical studies. “Many diseases manifest in sleep as well, such as epilepsy,” Reto Huber explains. “Using the new method, we hope to be able to manipulate those specific brain regions that are directly connected with the disease.” This could help improve the condition of affected patients.