No blue light, please, I'm tired: Light color determines sleepiness versus arousal in mice

August 15, 2016
Science Daily/PLOS
Light affects sleep. A study in mice shows that the actual color of light matters; blue light keeps mice awake longer while green light puts them to sleep easily.

Light shining into our eyes not only mediates vision but also has critical non-image-forming functions such as the regulation of circadian rhythm, which affects sleep and other physiological processes. As humans, light generally keeps us awake, and dark makes us sleepy. For mice, which are mostly nocturnal, light is a sleep-inducer. Previous studies in mice and humans have shown that non-image-forming light perception occurs in specific photosensitive cells in the eye and involves a light sensor called melanopsin. Mice without melanopsin show a delay in their response to fall asleep when exposed to light, pointing to a critical role for melanopsin in sleep regulation.

Stuart Peirson and Russell Foster, both from Oxford University, UK, alongside colleagues from Oxford and elsewhere, investigated this further by studying sleep induction in mice exposed to colored light, i.e., light of different wave lengths. Based on the physical properties of melanopsin, which is most sensitive to blue light, the researchers predicted that blue light would be the most potent sleep inducer.

To their surprise, that was not the case. Green light, it turns out, puts mice to sleep quickly, whereas blue light actually seems to stimulate the mice, though they did fall asleep eventually. Mice lacking melanopsin were oblivious to light color, demonstrating that the protein is directing the differential response.

Both green and blue light elevated levels of the stress hormone corticosterone in the blood of exposed mice compared with mice kept in the dark, the researchers found. Corticosterone levels in response to blue light, however, were higher than levels in mice exposed to green light. When the researchers gave the mice drugs that block the effects of corticosterone, they were able to mitigate the effects of blue light; drugged mice exposed to blue light went to sleep faster than control mice that had received placebos.

Citing previous results that exposure to blue light -- a predominant component of light emitted by computer and smart-phone screens -- promotes arousal and wakefulness in humans as well, the researchers suggest that "despite the differences between nocturnal and diurnal species, light may play a similar alerting role in mice as has been shown in humans." Overall, they say their work "shows the extent to which light affects our physiology and has important implications for the design and use of artificial light sources."

In the accompanying Primer, Patrice Bourgin, from the University of Strasbourg, France, and Jeffrey Hubbard from the University of Lausanne, Switzerland, say the study "reveals that the role of color [in controlling sleep and alertness] is far more important and complex than previously thought, and is a key parameter to take into account." The study's results, they say, "call for a greater understanding of melanopsin-based phototransduction and tell us that color wavelength is another aspect of environmental illumination that we should consider, in addition to photon density, duration of exposure and time of day, as we move forward in designing the lighting of the future, aiming to improve human health and well-being."
https://www.sciencedaily.com/releases/2016/08/160815185816.htm

When you don't feel valued in a relationship, sleep suffers

August 17, 2016
Science Daily/Society for Personality and Social Psychology
We spend up to one-third of our life asleep, but not everyone sleeps well. For couples, it turns out how well you think your partner understands and cares for you is linked to how well you sleep.

"Our findings show that individuals with responsive partners experience lower anxiety and arousal, which in turn improves their sleep quality," says lead author Dr. Emre Selçuk, a developmental and social psychologist at Middle East Technical University in Turkey.

One of the most important functions of sleep is to protect us against deteriorations in physical health. However, this protective function of sleep can only be realized when we have high quality uninterrupted sleep, known as restorative sleep.

Restorative sleep requires feelings of safety, security, protection and absence of threats. For humans, the strongest source of feelings of safety and security is responsive social partners -- whether parents in childhood or romantic partners in adulthood.

"Having responsive partners who would be available to protect and comfort us should things go wrong is the most effective way for us humans to reduce anxiety, tension, and arousal," says Selçuk.

The research supports findings from the past several years by an international collaboration of researchers including Emre Selçuk (Middle East Technical University, Turkey), Anthony Ong (Cornell University, US), Richard Slatcher and Sarah Stanton (Wayne State University, US), Gul Gunaydin (Bilkent University, Turkey), and David Almeida (Penn State, US).

Using data from the Midlife Development in the United States project, past projects from the researchers showed connections between partner responsiveness, physical health and psychological well-being over several years.

"Taken together, the corpus of evidence we obtained in recent years suggests that our best bet for a happier, healthier, and a longer life is having a responsive partner," says Selçuk.
https://www.sciencedaily.com/releases/2016/08/160817090618.htm

Disruptions to sleep patterns lead to an increased risk of suicides

August 24, 2016
Science Daily/Manchester University
The link between sleep problems and suicidal thoughts and behaviors is made starkly clear in new research.

In this study, conducted by researchers from the University's School of Health Sciences alongside the University of Oxford, 18 participants were interviewed about the role sleep problems have on suicidal tendencies.

Three inter-related pathways to suicidal thoughts were identified arising from sleep problems. The first was that being awake at night heightened the risks of suicidal thoughts and attempts, which in part was seen as a consequence of the lack of help or resources available at night.

Secondly, the research found that a prolonged failure to achieve a good night's sleep made life harder for respondents, adding to depression, as well as increasing negative thinking, attention difficulties and inactivity.

Finally, respondents said sleep acted as an alternative to suicide, providing an escape from their problems. However, the desire to use sleep as an avoidance tactic led to increased day time sleeping which in turn caused disturbed sleeping patterns -- reinforcing the first two pathways.

Donna Littlewood, lead author of the study, said the research has implications for service providers, such as health care specialist and social services.

"Our research underscores the importance of restoring healthy sleep in relation to coping with mental health problems, suicidal thoughts and behaviours.

"Additionally, night time service provision should be a key consideration within suicide prevention strategies, given that this study shows that those who are awake in the night are at an increased risk of suicide."
https://www.sciencedaily.com/releases/2016/08/160824111104.htm

'Morning people' self-sabotage less at night, night owls' less at sunrise

August 30, 2016
Science Daily/Indiana University
A study by psychological researchers shows that people are more likely to undermine their performance at stressful tasks when they're operating at 'peak capacity' based on their preferred time of the day.

The seemingly counterintuitive results, recently reported in the Journal of Experimental Social Psychology, are based on an investigation into the connection between people's circadian rhythm and risk of "self-handicapping," or self-sabotage. But rather than trying to protect against possible failure more at "off-peak" times, the study found, people actually engage in this behavior more at their peak times.

In other words, "morning people," who reported greater alertness at sunrise, self-handicapped more in the morning, and "night owls," who reported greater alertness at sunset, self-handicapped more in the evening.

Self-handicapping is defined by psychologists as when an individual seeks to protect their ego against potential failure in advance by creating circumstances -- real or imagined -- that harm their ability to carry out a stressful task. A classic example is failing to study or staying out too late the night before an important test or job interview.

The behavior also extends to mere claims of debilitating circumstances, such as imagined illness, fatigue or stress. Other studies have linked self-handicapping to other self-destructive behaviors, such as aggression, overeating and drug or alcohol addiction.

The study also found that people chronically prone to making excuses reported the same stress levels at "off-peak" hours as peers who do not engage in this behavior. Only at peak hours did these individuals report higher levels of stress as an excuse for poor performance.

"What this study tells us is that self-handicapping requires thought and planning," said Ed Hirt, professor in the IU Bloomington College of Arts and Sciences' Department of Psychological and Brain Sciences and an author on the study. "People who are feeling uncertain about themselves and start to fear that they might fail are more likely to identify potential excuses and self-handicap when they're at their peak than when they're not."

"When an individual's positive self-views are threatened, they may lash out against the source of the threat, compare themselves to others worse off than themselves, or engage in self-destructive actions, such as substance abuse," added Julie Eyink, a graduate student in Hirt's lab and lead author on the study. "Unfortunately, it's not uncommon to get caught in a negative spiral, in which self-handicapping leads to lower self-esteem and higher failure beliefs, which prompt more self-handicapping."

To conduct the study, IU researchers administered intelligent tests to 237 students (98 men and 139 women), half of whom were told that stress had been found to affect performance on the test and half of whom were told that stress should not affect the result.

The tests were randomly administered at 8 a.m. or 8 p.m. to volunteers who had been previously categorized as "night people" or "morning people" based upon a survey shown to accurately predict circadian rhythm. Study participants were also assessed for their tendency to self-sabotage through questions about their stress levels prior to the exam.

The tests and morning or night preference assessments were given two weeks apart, and participants were unaware that circadian rhythm would be a factor in the study. The individuals who administered the tests were unaware who had been labeled "morning people" or "night owls."

The results were that people who scored higher in terms of risk for self-sabotage reported greater stress levels at hours of peak performance.

A high or low tendency to self-sabotage did not make a difference at off-peak hours, however. Both groups reported the same stress levels at these times.

"The results seem counterintuitive, but what they really show is clear evidence that self-handicapping is a resource demanding strategy," said Eyink. "Only people who had their peak cognitive resources were able to engage in self-handicapping."

Based solely on the study, she said people who want to avoid self-sabotage might conclude they should engage in stressful tasks at off-peak times. But she also warns that such a strategy would require carrying out tasks at a time when a person lacks all the cognitive tools required to achieve top performance.

"Ultimately," she said, "I would advise that working to avoid self-handicapping -- through actions such as healthful practices, seeking help or counseling -- is the best strategy."

Other authors on the paper were Eric Galante and Kristin S. Hendrix, an undergraduate student and PhD student at IU Bloomington, respectively, at the time of the study.
https://www.sciencedaily.com/releases/2016/08/160830131200.htm

Adapting to stress: Understanding the neurobiology of resilience

September 2, 2016
Science Daily/Taylor & Francis
New research examines the way our bodies, specifically our brains, become “stress-resilient.” There is a significant variation in the way individuals react and respond to extreme stress and adversity—some individuals develop psychiatric conditions such as posttraumatic stress disorder or major depressive disorder—others recover from stressful experiences without displaying significant symptoms of psychological ill-health, demonstrating stress-resilience.

"Adapting to Stress: Understanding the Neurobiology of Resilience," an article recently published in Behavioral Medicine, examines the way our bodies, specifically our brains, become "stress-resilient." There is a significant variation in the way individuals react and respond to extreme stress and adversity -- some individuals develop psychiatric conditions such as posttraumatic stress disorder or major depressive disorder -- others recover from stressful experiences without displaying significant symptoms of psychological ill-health, demonstrating stress-resilience.

To understand why some individuals exhibit characteristics of a resilient profile, the interplay between neurochemical, genetic, and epigenetic processes over time needs to be explained. In this review, the authors examine the hormones, neuropeptides, neurotransmitters, and neural circuits associated with resilience and vulnerability to stress-related disorders.

About the importance of their article, the authors state: "In a period of international conflict as well as domestic pressures within the NHS, the study of stress and resilience has again become a prescient topic for both military and medical communities. The experience of extreme or prolonged stress does not necessarily result in mental health problems, which is an increasingly overlooked point and one of real significance to the field of psychopathology. Scientific evidence has consistently shown us that a high number of individuals are able to overcome stress and adversity and to continue on with productive lives. In this review, we summarize some of the latest findings underlying the neurobiology of resilience, which we hope will advance the understanding and treatment of stress-related psychiatric disorders."
https://www.sciencedaily.com/releases/2016/09/160902142232.htm

Brain circuit that drives sleep-wake states, sleep-preparation behavior is identified

September 5, 2016
Science Daily/Stanford University Medical Center
A brain circuit that's indispensable to the sleep-wake cycle has now been identified by researchers. This same circuit is also a key component of the reward system, an archipelago of interconnected brain clusters crucial to promoting behavior necessary for animals, including humans, to survive and reproduce.

It makes intuitive sense that the reward system, which motivates goal-directed behaviors such as fleeing from predators or looking for food, and our sleep-wake cycle would coordinate with one another at some point. You can't seek food in your sleep, unless you're an adept sleepwalker. Conversely, getting out of bed is a lot easier when you're excited about the day ahead of you.

But until this study, no precise anatomical location for this integration of the brain's reward and arousal systems has been pinpointed, said Luis de Lecea, PhD, professor of psychiatry and behavioral sciences.

The researchers' findings will be published online Sept. 5 in Nature Neuroscience. De Lecea is the senior author. The lead author is postdoctoral scholar Ada Eban-Rothschild, PhD.

"This has potential huge clinical relevance," de Lecea said. "Insomnia, a multibillion-dollar market for pharmaceutical companies, has traditionally been treated with drugs such as benzodiazepines that nonspecifically shut down the entire brain. Now we see the possibility of developing therapies that, by narrowly targeting this newly identified circuit, could induce much higher-quality sleep."

Some 25 to 30 percent of American adults are affected by sleep disturbances of one type or another, according to the National Institutes of Health. In addition, disruption of the sleep-wake rhythm typifies many different neuropsychiatric disorders and is understood to exacerbate them.

One of the first questions a psychiatrist asks a patient, said de Lecea, is, "How's your sleep?"

Similarity across vertebrates

The reward system's circuitry is similar in all vertebrates, from fish, frogs and falcons to fishermen and fashion models. A chemical called dopamine plays a crucial role in firing up this circuitry.

Neuroscientists know that a particular brain structure, the ventral tegmental area, or VTA, is the origin of numerous dopamine-secreting nerve fibers that run in discrete tracts to many different parts of the brain. A plurality of these fibers go to the nucleus accumbens, a forebrain structure particularly implicated in generating feelings of pleasure in anticipation of, or response to, obtaining a desired objective.

"Since many reward-circuit-activating drugs such as amphetamines that work by stimulating dopamine secretion also keep users awake, it's natural to ask if dopamine plays a key role in the sleep-wake cycle as well as in reward," Eban-Rothschild said. "But, in part due to existing technical limitations, earlier experimental literature has unearthed little evidence for the connection and, in fact, has suggested that this circuit probably wasn't so important."

For the new study, the investigators employed male laboratory mice bioengineered in several respects to enable the use of advanced technologies to remotely excite, suppress and monitor activity in the dopamine-secreting nerve cells from the mice's VTA. The researchers also measured the mice's overall brain activity and muscle tone to determine the mice's relative stages of asleep or arousal. They used video cameras to view the mice's behavior.

Observed in mice

Overall, activity in the dopamine-secreting nerve cells emanating from the VTA rose on waking and stayed elevated when mice were awake. Conversely, this activity ramped down when mice transitioned into sleep, remaining low while they slumbered. Activating this nerve-cell population was enough to rouse the animals from a sound sleep and keep them awake for long periods, even during a point in the mice's diurnal cycle when they'd ordinarily be bunking down. Control animals, whose VTA activity wasn't similarly jacked up, built little nests from pellets of materials placed in all the mice's cages and then promptly dropped off.

When instead the scientists suppressed activity in the same nerve-cell population during the typically active period of the mice's 24-hour cycle, the mice conked out, snoozing through the presence of surefire arousal triggers: delicious high-fat chow, a female or fear-inducing fox urine.

Mice in an unfamiliar cage ordinarily explore their new surroundings energetically. And indeed, VTA-suppressed mice stayed awake for the first 45 minutes of the hour they spent in a new cage. But Eban-Rothschild noticed something: They spent that waking time building nests.

"They were really careful about it," she noted. Once they were satisfied with what they'd built, they dozed off.

This wasn't just some stereotyped behavior guaranteed to emerge when VTA activity was inhibited, Eban-Rothschild added. "If we put the nest they'd already built in their usual cage into the novel cage, they climbed in and went right to sleep."

Control mice in the unfamiliar cage ran around, either ignoring the pellet of nesting materials placed inside or scattering those materials all over the cage.

Nest-making activities

Eban-Rothschild analyzed video footage of the animals' behavior in their novel environments, and correlated 1-second video segments with recorded brain activity during the corresponding time frame. She saw that actions directly connected to building nests were marked by reduced VTA activity, while actions that weren't were associated with higher levels of VTA activity.

"We knew stimulating the brain's dopamine-related circuitry would increase goal-directed behaviors such as food- and sex-seeking" said Eban-Rothschild. "But the new study shows that at least one complex behavior is induced not by stimulating, but by inhibiting, this very circuit. Interestingly, this behavior -- nest building -- is essential to a mouse's preparation for sleep."

Nobody had noticed that before, said de Lecea. "This is the first finding of a sleep-preparation starter site in the brain. It's likely we humans have one, too. If we're disrupting this preparation by, say, reading email or playing videogames, which not only give off light but charge up our emotions and get our VTA dopaminergic circuitry going, it's easy to see why we're likely to have trouble falling asleep."

Noting that this anticipatory phase is often at the root of many people's sleeping problems, de Lecea suggested that the newly identified circuit could be a target for pharmacological intervention to help people ease into sleep.

"We have plenty of drugs that counter dopamine," he said. "Perhaps giving a person the right dose, at just the right time, of a drug with just the right pharmacokinetic properties so its effect will wear off at the right time would work a lot better than bombarding the brain with benzodiazepines, such as Valium, that knock out the entire brain."

He said he also sees the possibility that drugs targeting the VTA's dopamine-secreting nerve cells could benefit those suffering from neurological conditions such as schizophrenia or bipolar disorder that are characterized by sleep-wake cycle disturbances.

"It could be that merely solving the sleep-wake part will clear up a lot of symptoms," de Lecea said.
https://www.sciencedaily.com/releases/2016/09/160905114515.htm

A new angle on anxiety Surprising findings specific brain cells as the key target

September 6, 2016
Science Daily/Boston Children's Hospital
Clinical anxiety affects up to 30 percent of Americans who are in great need of better treatments with fewer side effects. A study finds that certain neurons in the hypothalamus play a central, previously unknown role in triggering anxiety.
https://images.sciencedaily.com/2016/09/160906084828_1_540x360.jpg
In the 'gangplank' experiment, for example, the genetically altered mice were perfectly willing to venture onto an elevated maze, even the 'open' section whose protective walls were removed
Credit: Boston Children's Hospital

Experiments in mice showed that blocking the stress hormone corticotropin-releasing hormone (CRH) selectively in this group of neurons erased the animals' natural fears. Mice with the deletion readily walked elevated gangplanks, explored brightly lit areas and approached novel objects -- things normal mice avoid.

CRH, discovered nearly 40 years ago, coordinates our physical and behavioral stress response, often termed the "fight-or-flight" response. This response helps us survive in the face of threats, but when it is activated at the wrong time or too intensely, it can lead to anxiety and/or depression.

For this reason, several drug companies have developed CRH-blocking drugs as possible alternatives to SSRIs and benzodiazepines, which have side effects, for treating anxiety disorders. However, the results have been disappointing: of the eight completed phase II and III trials of CRH antagonists for depression or anxiety, six have been published, with largely negative findings, says Majzoub.

Zhang had a hunch that blocking CRH throughout the brain, as was done in the above drug trials, isn't the best approach. "Blocking CRH receptors all over the brain doesn't work," she says. "We think the effects work against each other somehow. It may be that CRH has different effects depending on where in the brain it is produced."

Using genetic engineering, Zhang and her colleagues selectively removed the CRH gene from about 1,000 nerve cells in the hypothalamus of mice. (To do this, they used a genetic trick, knocking out the gene only in cells expressing another gene called SIM1.)

The targeted cells were in the paraventricular nucleus, an area of the hypothalamus known to control the release of stress hormones (such as cortisol). But to Zhang's surprise, the loss of CRH in those cells affected not only hormone secretion, but also dramatically reduced anxiety behaviors (vigilance, suspicion, fear) in the mice.

"We already knew that CRH controlled the hormonal response, but the big surprise was that the behavioral response was completely blunted," says Majzoub. "It was a very robust finding: Every parameter we looked at indicated that this animal was much less inhibited."

In the "gangplank" experiment, for example, the genetically altered mice were perfectly willing to venture onto an elevated maze, even the "open" section whose protective walls were removed.

Similarly, when the mice were presented with an open field, the modified mice explored much more of its center, rather than hang out at the periphery like the control mice.

Another surprise was that CRH secreted in the paraventricular nucleus goes to more places in the brain than originally thought -- including areas that control the behavioral stress response. "It was a total surprise to us that the locus of control is in a tiny part of the hypothalamus," says Majzoub.

Majzoub acknowledges that blocking CRH production in just a subset of neurons would be technically challenging in humans. But if this could be done, it could be helpful for treating severe anxiety disorders or post-traumatic stress disorder (PTSD).

"Blocking just certain neurons releasing CRH would be enough to alter behavior in a major way," he says. "We don't know how to do that, but at least we have a starting point."
https://www.sciencedaily.com/releases/2016/09/160906084828.htm

Light causes drosophila to take longer midday nap

September 16, 2016
Science Daily/Julius-Maximilians-Universität Würzburg, JMU
Fruit flies' activity peaks especially in the morning and late afternoon. The insects extend their midday siesta on long summer days. Researchers have now found out what triggers this behavior. A miniature pair of eyelets discovered in the late 80s plays a crucial role in this context.
https://images.sciencedaily.com/2016/09/160916093047_1_540x360.jpg
The large compound eyes left and right are clearly recognizable in the head of the fruit fly. The four-cell Hofbauer-Buchner eyelet (yellow; only one eyelet shown in the drawing) is located underneath the compound eye. From the eyelets, nerve fibers (also yellow) run directly to the clock network in the fly's brain.
Credit: Team Helfrich-Förster

In 1989, the Würzburg biologists Alois Hofbauer and Erich Buchner reported a surprising finding in the journal "Naturwissenschaften": They had identified a new pair of eyelets in drosophila unknown until then. The fruit fly was considered an important model organism for zoologists and geneticists even back then with scores of scientists showing an interest in the tiny insect. But they had all failed to detect the additional eyes -- no wonder given their microscopic size: Each eyelet consists of just four photoreceptor cells.

In spite of this, the Hofbauer-Buchner eyelets seem to play a major role in the life of drosophila. A study conducted by scientists from the University of Würzburg with colleagues from the University of Michigan and the University of Bristol has come to this conclusion.

Drosophila's activity peaks in the morning and in the late afternoon and they rest during the hottest time of the day. The tiny sensory organs evidently influence when this midday siesta ends. "On long summer days, they delay the onset of the afternoon activity phase," explains Professor Charlotte Helfrich-Förster from the University of Würzburg's Biocenter.

Hardwired in the fly's brain

The scientist has studied drosophila's circadian rhythms for years. In the current study, her research team has been able to show for the first time that the Hofbauer-Buchner eyelets are wired to a clock neuron network in the flies' brain: Nerve fibres run directly from the eyelets to two groups of clock neurons. One of them is responsible for the morning activity whereas the other influences the evening activity.

"At daybreak, light falls onto the eyelets," Helfrich-Forster details. "This light input triggers the production of the two neurotransmitters histamine and acetylcholine. We suppose that acetylcholine activates the neurons relevant for morning activity. At the same time, the histamine seems to indirectly inhibit the circadian clock for the evening peak phase thereby extending the phase of inactivity." Hence, the Hofbauer-Buchner eyelets are part of a complex network that governs drosophila's sleep/activity rhythm.

Mammalian clock similar to that of flies

Another reason why the findings are interesting is because the circadian clocks of animals have changed comparably little in the course of evolution. "Mice, for example, have a neuronal clock network in their brains that shares many similarities with that of the fruit fly," Helfrich-Förster emphasises. "Therefore, drosophila allows us to get deep insights into the circadian clock of mammals and probably into that of humans, too."
https://www.sciencedaily.com/releases/2016/09/160916093047.htm

Lack of interest in sex successfully treated by exposure to bright light

September 18, 2016
Science Daily/European College of Neuropsychopharmacology (ECNP)
Exposure to bright light increases testosterone levels and leads to greater sexual satisfaction in men with low sexual desire. These are the results of a pilot randomised placebo-controlled trial.

Low sexual desire affects significant numbers of men after the age of 40, with studies finding that up to 25% of men report problems*, depending on age and other factors. Scientists had previously noted that sexual interest varies according to the seasons, prompting the idea that levels of ambient light may contribute to sexual desire.

Now a group of scientists from the University of Siena in Italy have tested sexual and physiological responses to bright light. They found that regular, early-morning, use of a light box -- similar to those used to combat Seasonal Affective Disorder -- led both to increased testosterone levels and greater reported levels of sexual satisfaction.

The scientists, led by Professor Andrea Fagiolini, took recruited 38 men who had been attending the Urology Department of the University of Siena following a diagnosis of hypoactive sexual desire disorder or sexual arousal disorder -- both conditions which are characterised by a lack of interest in sex. Each man underwent an initial evaluation to determine the baseline level of interest in sex, with testosterone levels also being measured.

The researchers then divided the men into two groups. One group received regular treatment with a specially adapted light box, the control (placebo) group was treated via a light box which had been adapted to give out significantly less light. Both groups were treated early in the morning, with treatment lasting half an hour per day. After two weeks of treatment or placebo, the researchers retested sexual satisfaction and testosterone levels.

Professor Fagiolini said "We found fairly significant differences between those who received the active light treatment, and the controls. Before treatment, both groups averaged a sexual satisfaction score of around 2 out of 10, but after treatment the group exposed to the bright light was scoring sexual satisfaction scores of around 6.3 -- a more than 3-fold increase on the scale we used. In contrast, the control group only showed an average score of around 2.7 after treatment."

The researchers also found that testosterone levels increased in men who had been given active light treatment. The average testosterone levels in the control group showed no significant change over the course of the treatment -- it was around 2.3 ng/ml at both the beginning and the end of the experiment. However, the group given active treatment showed an increase from around 2.1 ng/ml to 3.6 ng/ml after two weeks.

Professor Fagiolini explained: "The increased levels of testosterone explain the greater reported sexual satisfaction. In the Northern hemisphere, the body's Testosterone production naturally declines from November through April, and then rises steadily through the spring and summer with a peak in October. You see the effect of this in reproductive rates, with the month of June showing the highest rate of conception. The use of the light box really mimics what nature does.

We believe that there may be several explanations to explain the underlying mechanism. For instance, light therapy inhibits the pineal gland in the centre of the brain and this may allow the production of more testosterone, and there are probably other hormonal effects. We're not yet at the stage where we can recommend this as a clinical treatment. Even at that stage, there will be a few patients -- for example those with an eye condition or anyone taking medicines which affect light sensitivity (some antidepressants, and some antibiotics, for example) -- who would need to take special care. However if this treatment can be shown to work in a larger study, then light therapy may offer a way forward. It's a small study, so for the moment we need to treat it with appropriate caution."

The researchers note that there are several possible reasons for lack of sexual desire. Treatment depends on the underlying cause, but current therapeutic options include testosterone injections, antidepressants, and other medications. The researchers believe that light therapy may offer the benefits of medication, but with fewer side effects.

Commenting, Professor Eduard Vieta (Chair of the Department of Psychiatry and Psychology at the University of Barcelona Hospital Clinic and treasurer of the ECNP) said: "Light therapy has been used successfully in the past to treat some forms of depression and this study suggests now that it may also work to treat low sexual desire in men. The mechanism of action appears to be related to the increase of testosterone levels. Before this kind of treatment, which is likely to be better tolerated than pharmacological therapy, gets ready for its routine use, there are many steps to be implemented, including replication of the results in a larger, independent study, and verifying whether the results are long-lasting and not just short-term."
https://www.sciencedaily.com/releases/2016/09/160918214443.htm

Sleep is key to curing chronic pain

September 21, 2016
Science Daily/University of Warwick
A ink between chronic pain and lack of sleep has been identified by a team of researchers. They also discovered that people with pain who believe they won't be able to sleep are more likely to suffer from insomnia, thus causing worse pain. A pioneering study could lead to specific cognitive therapy to cure insomnia and treat chronic pain.

Researchers from the Sleep and Pain Lab in the Department of Psychology have demonstrated that conditions like back pain, fibromyalgia, and arthritis are directly linked with negative thoughts about insomnia and pain, and this can be effectively managed by cognitive-behavioural therapy (CBT).

Esther Afolalu and colleagues have formulated a pioneering scale to measure beliefs about sleep and pain in long-term pain patients, alongside their quality of sleep -- the first of its type to combine both pain and sleep and explore the vicious cycle between sleep and pain problems.

The scale was tested on four groups of patients suffering from long-term pain and bad sleeping patterns, with the result showing that people who believe they won't be able to sleep as a result of their pain are more likely to suffer from insomnia, thus causing worse pain.

The results show that the scale was vital in predicting patients' level of insomnia and pain difficulties. With better sleep, pain problems are significantly reduced, especially after receiving a short course of CBT for both pain and insomnia.

The study has provided therapists the means with which to identify and monitor rigid thoughts about sleep and pain that are sleep-interfering, allowing the application of the proven effective CBT for insomnia in people with chronic pain.

Esther Afolalu explains: "Current psychological treatments for chronic pain have mostly focused on pain management and a lesser emphasis on sleep but there is a recent interest in developing therapies to tackle both pain and sleep problems simultaneously. This scale provides a useful clinical tool to assess and monitor treatment progress during these therapies."

Dr. Nicole Tang, the study senior author, comments: "Thoughts can have a direct and/or indirect impact on our emotion, behaviour and even physiology. The way how we think about sleep and its interaction with pain can influence the way how we cope with pain and manage sleeplessness. Based on clinical experience, whilst some of these beliefs are healthy and useful, others are rigid and misinformed. The new scale, PBAS, is developed to help us pick up those beliefs that have a potential role in worsening the insomnia and pain experience."
https://www.sciencedaily.com/releases/2016/09/160921084808.htm