ADHD kids can be still, if they're not straining their brains

ADHD symptoms manifest watching videos requiring executive brain function

September 18, 2017

Science Daily/University of Central Florida

Lack of motivation or boredom with school isn't to blame for squirming by children with Attention Deficit Hyperactivity Disorder. Symptoms such as fidgeting, foot-tapping and chair-swiveling are triggered by cognitively demanding tasks - like school and homework. But movies and video games don't typically require brain strain, so the excessive movement doesn't manifest.

How's this for exasperating: Your ADHD child fidgets and squirms his way through school and homework, but seems laser-focused and motionless sitting in front of the TV watching an action thriller.

Well, fret not, because new research shows lack of motivation or boredom with school isn't to blame for the differing behavior. It turns out that symptoms of Attention Deficit Hyperactivity Disorder such as fidgeting, foot-tapping and chair-swiveling are triggered by cognitively demanding tasks -- like school and homework. But movies and video games don't typically require brain strain, so the excessive movement doesn't manifest.

"When a parent or a teacher sees a child who can sit perfectly still in one condition and yet over here they're all over the place, the first thing they say is, 'Well, they could sit still if they wanted to,'" said Mark Rapport, director of the Children's Learning Clinic at the University of Central Florida. "But kids with ADHD only need to move when they are accessing their brain's executive functions. That movement helps them maintain alertness."

Scientists once thought that ADHD symptoms were always present. But previous research from Rapport, who has been studying ADHD for more than 36 years, has shown the fidgeting was most often present when children were using their brains' executive functions, particularly "working memory." That's the system we use for temporarily storing and managing information required to carry out complex cognitive tasks such as learning, reasoning and comprehension.

As recently published in the Journal of Abnormal Child Psychology, Professor Rapport's senior doctoral student Sarah Orban and research team tested 62 boys ages 8 to 12. Of those, 32 had ADHD. Thirty did not have ADHD and acted as a control group.

During separate sessions, the children watched two short videos, each about 10 minutes long. One was a scene from "Star Wars Episode I -- The Phantom Menace" in which a young Anakin Skywalker competes in a dramatic pod-race. The other was an instructional video featuring an instructor verbally and visually presenting multistep solutions to addition, subtraction and multiplication problems.

While watching, the participants were observed by a researcher, recorded and outfitted with wearable actigraphs that tracked their slightest movements. The children with ADHD were largely motionless while watching the Start Wars clip, but during the math video they swiveled in their chairs, frequently changed positions and tapped their feet.

That may not seem surprising. After all, weren't the children absorbed by the sci-fi movie and bored by the math lesson? Not so, Rapport said.

"That's just using the outcome to explain the cause," he said. "We have shown that what's really going on is that it depends on the cognitive demands of the task. With the action movie, there's no thinking involved -- you're just viewing it, using your senses. You don't have to hold anything in your brain and analyze it. With the math video, they are using their working memory, and in that condition movement helps them to be more focused."

The takeaway: Parents and teachers of children with ADHD should avoid labeling them as unmotivated slackers when they're working on tasks that require working memory and cognitive processing, researchers said.

The study builds on Rapport's earlier research, including a 2015 study that found that children with ADHD must be allowed to squirm to learn.

Video: https://www.youtube.com/watch?v=167se17RNHw

https://www.sciencedaily.com/releases/2017/09/170918222249.htm

High blood pressure reasons differ by gender in teens; young adults

September 17, 2017

Science Daily/American Heart Association

Gender matters when it comes to what's most likely to elevate blood pressure in young to middle-aged adults. The volume of blood pumped from the left ventricle during heartbeats, i.e., stroke volume, is the main determinant of blood pressure levels in women, while blood pressure in men is more likely to be determined by the amount of resistance in the body's blood vessels.

There are marked gender differences in what drives blood pressure in middle-age in adulthood, suggesting the need for gender-specific treatments for high blood pressure, according to research presented today at the American Heart Association (AHA) Council on Hypertension, AHA Council on Kidney in Cardiovascular Disease, American Society of Hypertension Joint Scientific Sessions 2017, in San Francisco.

Background

"Blood pressure is determined mainly by three factors: heart rate; stroke volume, which is the volume of blood pumped by the heart; and the resistance to blood flow through the vessels, called total peripheral resistance. An increase in any one of the three factors can lead to an increase in blood pressure," said study author Catriona Syme, Ph.D., postdoctoral fellow at The Hospital for Sick Children (SickKids) in Toronto, Ontario, Canada. "The key takeaway from this study is that, for young and middle-aged women, stroke volume was the main determinant of blood pressure, while, in men, vascular resistance was the main determinant of blood pressure."

Syme and colleagues studied 1,347 Canadians from the Saguenay Youth Study, including 911 adolescents and 426 adults ages 36 to 65 years. The researchers used a device that measures beat-by-beat blood pressure and the underlying forces of heart rate, stroke volume and total peripheral resistance. In the approximately hour-long protocol, they measured these variables at rest, and during posture changes and a mental stressor -- all designed to mimic daily life activities, according to Syme.

Researchers found:

In females, stroke volume explains 55 percent of the variance in systolic blood pressure (the top number in a blood pressure reading), versus only 35 percent in males.

In males, the major determinant of systolic blood pressure was total peripheral resistance, which explained 47 percent of the variance, versus only 30 percent in females.

These gender differences were seen across most of the 52-minute protocol, being most prominent during standing and least evident during mental stress, according to the abstract.

This study is novel in that it looks at the relative contributions of the three parameters determining blood pressure, which have not been evaluated in a large population-based study, and it assesses these factors over time, in a way that mimics daily life activities. The study also looks at high blood pressure culprits in adolescents and young to middle aged adults, who are not frequently studied despite being affected by hypertension, according to Syme.

"For example, there have been many studies looking at sex differences in the usefulness of blood pressure medications. But, most of those studies have been done in people whose average age was 60-70 years -- many of the women being post-menopausal," Syme said. "We think pre-menopausal women and men of a similar age may have elevated blood pressure for different reasons, and thus may need to be treated for hypertension differently. After menopause, when the production of female sex hormones decreases, reasons for hypertension may be more similar in men and women."

While current treatment recommendations for hypertension do not differ by gender across all ages, this study suggests potential benefits to prescribing blood pressure-lowering medications with consideration for gender differences in the underlying physiology of elevated blood pressure in young and middle-aged adults.

This study was conducted in Caucasians. Future studies should investigate whether the relative contributions of these parameters differ by race.

https://www.sciencedaily.com/releases/2017/09/170917151002.htm

Teens come 'jet lagged' to school: Shifting sleeping patterns at weekends

September 15, 2017

Science Daily/Örebro University

A lack of sleep is associated with more absence and teens turn up jet lagged to school on Mondays, as shown in new research.

"My research is about understanding young people's sleeping patterns and what factors are linked to these. I am interested in why so many young people do not get enough sleep and what can be done about it," says Serena Bauducco, linked to the School of Law, Psychology and Social Work at Örebro University.

She has now presented her thesis showing that for teens who do not get enough sleep, their mental well-being is affected. Their sleep routines are not as good and they are more stressed and worried about school than those who get the sleep they need. These young people also bring their mobile phone or computer to bed to a greater extent than others.

In her thesis, Serena Bauducco also shows that problems with sleep are directly linked to a higher degree of absence from school.

"Those teens that showed symptoms of difficulties sleeping had three times as much absence than those who did not. That is quite a lot."

"We also checked other things that may be related to a high level of absence -- for example bullying, depression and anxiety. But the correlation between difficulties sleeping and why they did not go to school was very clear."

Her thesis is based on a study of approximately 2,700 upper secondary school pupils, aged 13-16. The study shows that teens sleep longer at weekends. And because they go to bed later and wake up later, they turn up for school with a changed sleeping cycle. In other words -- they suffer from jet lag.

"As a result, they may be tired and grumpy at school. Studies show that not getting enough sleep may affect learning," says Serena Bauducco.

For some, it may take three to four days to get back into routine -- and by then, the school week is nearly over. But for the large majority, the weekend-related jet lag is not a big deal. Almost all teens in the study did suffer from jet lag, but a majority of them did get enough sleep during the week.

"Nevertheless, it was still 20 per cent of those taking part in the study that on the whole did not get enough sleep," says Serena Bauducco.

As children approach adolescence, they develop later evening habits and it takes them longer to get to sleep once they have gone to bed. This is a natural part of their development, but it can obviously still be difficult to manage.

Serena Bauducco and her research colleagues therefore set up a programme with upper secondary school pupils in Örebro. The aim was to help the teens to create routines for themselves to get good sleep. It included simple things like not bringing their mobile phone into bed with them, and not sending or responding to text messages after 10 o'clock at night. But it also emphasised the importance of planning their time to make room for both school, spare time -- and sleep.

"One outcome was that those who had previously got the least sleep, improved their sleeping routines. They were less stressed and slept better."

So can you draw the conclusion that those teens who do not sleep very well, also find school work difficult?

"It is not something that we have looked at, but there are other studies that point to that."

There are schools in Sweden that have introduced later school start times to adjust to teenagers' biological rhythm. Some researchers say that sleeping in may lead to pupils performing better at school.

Serena Bauducco thinks this is an interesting development.

"A later start to the school day would lead to so many other things; staff have to change their working hours, bus time tables need changing and so on. I still think it is worth a try, as long as you also evaluate the effects of such structural change."

https://www.sciencedaily.com/releases/2017/09/170915164815.htm

Is ADHD really a sleep problem?

September 4, 2017

Science Daily/European College of Neuropsychopharmacology

Around 75 percent of children and adults with attention deficit hyperactivity disorder (ADHD) also have sleep problems, but until now these have been thought to be separate issues. Now a in a pulling together of the latest research, Scientists are proposing of a new theory which says that much of ADHD may in fact be a problem associated with lack of regular circadian sleep.

Presenting the proposal at the ECNP Conference in Paris, Professor Sandra Kooij (Associate Professor of Psychiatry at VU University Medical Centre, Amsterdam and founder and chair of the European Network Adult ADHD) said:

"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."

Professor Kooij laid out the links which have led to the synthesis:

• ·      In 75% of ADHD patients, the physiological sleep phase -- where people show the physiological signs associated with sleep, such as changes in the level of the sleep hormone melatonin, and changes in sleep-related movement -- is delayed by 1.5 hours.
• ·      Core body temperature changes associated with sleep are also delayed (reflecting melatonin changes)
• ·      Many sleep-related disorders are associated with ADHD, including restless-leg syndrome, sleep apnea, and the circadian rhythm disturbance, the delayed sleep phase syndrome
• ·      ADHD people often show greater alertness in the evening, which is the opposite of what is found in the general population
• ·      Many sufferers benefit from taking melatonin in the evening or bright light therapy in the morning, which can help reset the circadian rhythm
• ·      Recent work has shown that around 70% of adult ADHD sufferers show an oversensitivity of the eyes to light, leading many to wear sunglasses for long periods during the day -- which may reinforce the problems associated with a 'circadian shift'.
• ·      Chronic late sleep leads to a chronic sleep debt, associated with obesity, diabetes, cardiovascular disease and cancer. This cascade of negative health consequences may in part be preventable by resetting the sleep rhythm.
•  

Professor Kooij continued:

"We are working to confirm this physical-mental relationship by finding biomarkers, such as Vitamin D levels, blood glucose, cortisol levels, 24 hour blood pressure, heart rate variability, and so on. If the connection is confirmed, it raises the intriguing question: does ADHD cause sleeplessness, or does sleeplessness cause ADHD? If the latter, then we may be able to treat some ADHD by non-pharmacological methods, such as changing light or sleep patterns, and prevent the negative impact of chronic sleep loss on health."

"We don't say that all ADHD problems are associated with these circadian patterns, but it looks increasingly likely that this is an important element."

Commenting, Professor Andreas Reif (University Hospital, Frankfurt, and leader of the EU CoCA project on ADHD ), who was not involved in the research, said "A disturbance of the circadian system may indeed be a core mechanism in ADHD, which could also link ADHD to other mental illnesses such as depression or bipolar disorder. But also beyond these pathophysiological considerations, sleep problems and abnormalities of circadian rhythms are a huge problem for many patients, heavily impacting on their social life" He continued "More research into the interconnections between ADHD and the "inner clock" is thus very relevant to improve patients' lives and to shed light on the disease mechanism of ADHD."

Note: Attention deficit hyperactivity disorder (ADHD) is a group of behavioural symptoms with a neurobiological background, that include inattentiveness, hyperactivity, mood swings and impulsiveness. ADHD is highly heritable, and several differences in brain volume and function have been shown compared to controls. Symptoms of ADHD tend to be noticed at an early age and may become more noticeable when a child's circumstances change, such as when they start school. Most cases are diagnosed when children are 6 to 12 years old, but ADHD is also increasingly recognised in adults and older people, as ADHD can persist during the lifespan. People with ADHD often have additional problems, such as sleep, mood- and anxiety disorders. Between 2 and 5 % of children, adults and older people suffer from ADHD.

https://www.sciencedaily.com/releases/2017/09/170904093443.htm

How reading and writing with your child boost more than just literacy

August 31, 2017

Science Daily/University of Washington

Children who read and write at home -- whether for assignments or just for fun -- are building long-term study and executive function skills, according to a new article

And while home literacy activities have already been associated with higher test scores, the new study shows these activities also provide students with tools for lifetime success.

"People who are good students tend to become good employees by being on time and putting forward their best work. All of the things that make you a good student also make you a good employee," said Nicole Alston-Abel, a Federal Way Public Schools psychologist who conducted the study while pursuing her doctorate at the UW. "If you make sure your child is academically engaged at home through third grade, kids go on autopilot -- they know how to 'do' school after that."

Alston-Abel analyzed data collected by co-author Virginia Berninger, UW emeritus professor of education, who conducted a five-year longitudinal study of academic performance in grades one through seven. As part of that study, Berninger sent home questionnaires asking parents if, and how, they helped their children with reading and writing; Alston-Abel, a former primary teacher, then compared the responses with students' academic performance.

The study published online in May in the Journal of Educational and Psychological Consultation.

To collect a range of ages and school experiences, the study followed two groups of students in public elementary schools near the UW campus -- one cohort of students from first to fifth grade, the other from third to seventh grade. In all, 241 families participated over five years, completing annual questionnaires about how their child felt about reading and writing, what kinds of activities they engaged in at home, and what kind of help parents provided.

The demographics of both cohorts reflected neighborhoods around the university: About 85 percent of students were white or Asian American, and nearly three-fourths of parents had a bachelor's or advanced degree. A more diverse pool, Alston-Abel said, would be illuminating from a research perspective, but the basic message would remain the same: "The takeaway is still the importance of having a parent involved in developing the habits and models a child needs to be successful. It doesn't matter what socioeconomic status you come from."

Among the study's findings:

Students spent significantly more time at home reading than writing.

• ·      Without a specific assignment, children were more likely to choose reading as an activity than writing.
• ·      Parents provided more help with writing than with reading.
• ·      Starting at the intermediate grades (four and up), writing assignments increased, while parent help for writing declined more gradually than for reading.
• ·      About three-fourths of the fifth- and seventh-grade students used a computer for writing assignments.
• ·      Parents of those older students described their children as "fluent" in using a computer for writing homework for 19 percent of the fifth-graders, and 53 percent of the seventh-graders.
• ·      Parent ratings of their student's "self-regulation," or ability to stay on task and exhibit other study skills, were associated with academic performance, especially in reading comprehension and written expression.
•  

The authors point out that there is no direct causal link between the responses on the questionnaires and student achievement, but that some patterns do exist. For example, among students whose parents described their lack of focus or unwillingness to help set modest goals, academic achievement was generally lower than among students who stayed on task or learned to prioritize.

The study speaks to the need for a collaborative effort between parents and teachers, Alston-Abel said, especially among marginalized populations, and at a time when kindergarteners, according to Common Core State Standards, are expected to demonstrate basic reading and writing skills.

"Some kids come to kindergarten reading basic 'sight words,' and others don't know their letters. Add up the disadvantages and the demands of the curriculum, and it becomes very apparent that if you don't have a collaborative effort, for these same kids, that gap is always going to be there," Alston-Abel said.

Teachers can start by asking parents about how they support their child's learning at home -- like with the kinds of questionnaires used in the study. The responses to open-ended questions about what kinds of reading and writing a child does at home, why, and for how long each week, can then inform instruction. Meanwhile, parents who work with their children, Alston-Abel added, are introducing study skills like time management and impulse control.

The paper provides other tips for parents and teachers on how to work together to develop literacy and study skills. One way is to engage a child in writing at home through journals, a story to a family member, even an email or thank-you note. Another is to look for specific skills to help develop, such as spelling or reading comprehension, but pull back when the child appears able to accomplish more independently. And encourage any opportunity to read or write for fun.

"Academic success is an all-hands-on-deck enterprise," Alston-Abel said. "Teacher, parent and student all have a part to play. Fostering home-school partnerships that enhance and extend the experience of the learner can lead to life-long habits that foster success."

https://www.sciencedaily.com/releases/2017/08/170831102149.htm

Children's sleep quality linked to mothers' insomnia

August 31, 2017

Science Daily/University of Warwick

Children sleep more poorly if their mothers suffer from insomnia symptoms – potentially affecting their mental wellbeing and development - according to new research. Nearly 200 school kids and their parents were studied, results indicating that children whose mothers have insomnia symptoms fall asleep later, get less sleep and spend less time in deep sleep. There appeared to be no link between fathers’ insomnia symptoms and children’s sleep.

Led by Dr Sakari Lemola from Warwick's Department of Psychology and Natalie Urfer-Maurer from the University of Basel, the study reported in Sleep Medicine shows that children of mothers with insomnia symptoms fall asleep later, get less sleep, and spend less time in deep sleep.

Analysing data from nearly 200 healthy 7-12 year old children and their parents, the researchers studied the relationship between the parents' insomnia symptoms and their children's sleep quality.

Sleep was assessed in the children during one night with in-home electroencephalography (EEG) -- a method used to record electrical activity in the brain and makes it possible to identify different sleep stages -- whilst parents reported their own insomnia symptoms and their children's sleep problems.

The researchers found that children whose mothers have insomnia symptoms fall asleep later, get less sleep, and spend less time in deep sleep, as measured by EEG.

However, there was no association between the fathers' sleep problems and children's sleep as measured by EEG.

The study suggests that the reason why children's sleep is more closely related to mothers' sleep than to fathers' sleep is that, on average, mothers still spend more time with their children than fathers -- and therefore, a stronger mutual influence is likely.

When parents reported their children's sleep, both mothers and fathers with sleep problems more often reported that their children had difficulties getting into bed and did not sleep enough.

Sleep plays an essential role for adults' and children's well-being. Short sleep and poor sleep quality can affect mental health, learning, memory, and school achievement in children. In adulthood around 30% of people suffer from disturbed sleep. The most common sleep disorder in adulthood is insomnia, which is defined by symptoms such as difficulty falling or staying asleep at night.

"These findings are important because sleep in childhood is essential for wellbeing and development," commented Dr Sakari Lemola. "The findings show that children's sleep has to be considered in the family context. In particular, the mother's sleep appears to be important for how well school-aged children sleep."

Several mechanisms could account for the relationship between parents' and children's sleep. First, children may learn sleep habits from their parents. Second, poor family functioning could affect both parents' and children's sleep. For instance, family fights in the evening before bedtime may prevent the whole family from a good night's sleep.

Third, it is possible that parents suffering from poor sleep show "selective attention" for their own as well as their children's sleep problems, leading to increased monitoring of sleep. It is possible that increased monitoring and attempts to control sleep may negatively affect sleep quality. Finally, children may also share genes with their parents that predispose them to poor sleep.

The research, 'The association of mothers' and fathers' insomnia symptoms with school-aged children's sleep assessed by parent report and in-home sleep-electroencephalography', is published in Sleep Medicine.

https://www.sciencedaily.com/releases/2017/08/170831093352.htm

Exclusion from school can trigger long-term psychiatric illness

August 29, 2017

Science Daily/University of Exeter

Excluding children from school may lead to long-term psychiatric problems and psychological distress, a study of thousands of children has shown.

Research by the University of Exeter, published in the journal Psychological Medicine found that a new onset mental disorder may be a consequence of exclusion from school.

The study, also found that -- separately -- poor mental health can lead to exclusion from school.

Professor Tamsin Ford, a child and adolescent psychiatrist at the University of Exeter's Medical School, warned that excluded children can develop a range of mental disorders, such as depression and anxiety as well as behavioural disturbance. The impact of excluding a child from school on their education and progress is often long term, and this work suggests that their mental health may also deteriorate.

The study is the most rigorous study of the impact of exclusion from school among the general population so far and included a standardised assessment of children's difficulties.

Consistently poor behaviour in the classroom is the main reason for school exclusion, with many students, mainly of secondary school age, facing repeated dismissal from school. Relatively few pupils are expelled from school, but Professor Ford warned that even temporary exclusions can amplify psychological distress.

Professor Ford, who practises as a child and adolescent psychiatrist as well as carrying out research, said identifying children who struggle in class could, if coupled with tailored support, prevent exclusion and improve their success at school, while exclusion might precipitate future mental disorder. These severe psychological difficulties are often persistent so could then require long-term clinical support by the NHS.

Professor Ford said: "For children who really struggle at school, exclusion can be a relief as it removes then from an unbearable situation with the result that on their return to school they will behave even more badly to escape again. As such, it becomes an entirely counterproductive disciplinary tool as for these children it encourages the very behaviour that it intends to punish. By avoiding exclusion and finding other solutions to poor behaviour, schools can help children's mental health in the future as well as their education."

Exclusion from school is commoner among boys, secondary school pupils, and those living in socio-economically deprived circumstances. Poor general health and learning disabilities, as well as having parents with mental illness, is also associated with exclusion.

The analysis by a team led by Professor Ford of responses from over 5000 school-aged children, their parents and their teachers in the British Child and Adolescent Mental Health Surveys collected by the Office of National Statistics on behalf of the Department of Health found that children with learning difficulties and mental health problems such as depression, anxiety, ADHD and autism spectrum conditions were more likely to be excluded from the classroom.

The research team found more children with mental disorder among those who had been excluded from school, when they followed up on their progress, than those who had not. The research team omitted children who had a previous mental disorder from this analysis.

The researchers concluded there is a 'bi-directional association' between psychological distress and exclusion: children with psychological distress and mental-health problems are more likely to be excluded in the first place but exclusion predicted increased levels of psychological distress three years later.

Claire Parker, a researcher at the University of Exeter Medical School, who carried out doctoral research on the project said:

"Although an exclusion from school may only last for a day or two, the impact and repercussions for the child and parents are much wider. Exclusion often marks a turning point during an ongoing difficult time for the child, parent and those trying to support the child in school."

Most research into the impact of exclusion has so far involved the study of individuals' experience and narratives from much smaller groups of people chosen because of their experience, which may not be so representative.

This study included an analysis of detailed questionnaires filled in by children parents and teachers as well as an assessment of disorder by child psychiatrists, drawing on data from over 5000 children in two linked surveys to allow the researchers to compare their responses with students who had been excluded. This sample from the general population included over 200 children who had experienced at least one exclusion.

The report concluded: "Support for children whose behaviour challenges school systems is important. Timely intervention may prevent exclusion from school as well as future psychopathology. A number of vulnerable children may face exclusion from school that might be avoided with suitable interventions."

Professor Ford added: "Given the established link between children's behaviour, classroom climate and teachers' mental health, burn out and self-efficacy, greater availability of timely support for children whose behaviour is challenging might also improve teachers' productivity and school effectiveness" .

https://www.sciencedaily.com/releases/2017/08/170829124507.htm

Brain stimulation for children with learning difficulties?

August 29, 2017

Science Daily/University of Oxford

Applying a brain stimulation method, which was previously suggested to enhance mathematical learning in healthy adults, may improve the performance of children with mathematical learning difficulties, according to an exploratory study.

The early stage, small-scale study, which has been published in Nature's open access journal Scientific Reports, involved twelve children between the ages of eight and eleven with learning difficulties in mathematics.

The study took place at Fairley House, a specialist day school for children with specific learning difficulties in London. After careful safety screening, the children were split into two groups of six. One group wore a cap attached to a light, battery-operated device through which painless low electrical current was applied over the left and right areas on the forehead, above regions of the brain called the dorsolateral prefrontal cortices. This region has been highlighted to play a role in mathematical learning.

The method of stimulation, which is known as transcranial random noise stimulation (tRNS), was applied in nine 20-minute sessions over 5 weeks.

The other group wore an identical cap but did not receive any stimulation. Children did not detect reliably whether they received stimulation or not.

While wearing the caps, the children in both groups played a specially-designed numerical training game developed by the researchers, which integrates numerical learning and visuospatial components, with bodily movements, while the game changed its level adaptively based on the child's performance.

Immediately before and after the trial, the researchers also measured their performance in a mathematical test called MALT, a standardized diagnostic tool calibrated to the UK's national curriculum.

They found that stimulation yields a mixed effect in term of performance but improved the learning of children during the numerical training game, compared to those who wore the 'placebo' cap.

The results also hinted that the positive effects of tRNS have contributed to improved results on the MALT test.

These findings resemble previous studies on healthy adults that suggested tRNS over the same regions of the brain improved arithmetic learning compared to the control group, and generalised to related materials that were not specifically trained.

Professor Roi Cohen Kadosh of Oxford University's Department of Experimental Psychology, said: 'Compared to children without learning difficulties, children with learning difficulties have a brain that works differently. This is usually associated with poor learning, and in turn might impair typical brain development.

'Learning difficulties are usually treated by behavioural interventions, but these have shown little efficacy, especially in brains with neural atypicalities. Our research suggests that children with learning difficulties might benefit from combining their learning with tRNS, which has been suggested to improve learning and alter brain functions in healthy adults.'

But the authors warn that this study is just the first step from a scientific perspective. To understand the potential of tRNS for improving learning and cognition of children with learning difficulties, we need to run more studies, and see whether these results replicate. We also need to understand the neural mechanisms that support such improvements in learning.

'Maths is something that many people find challenging, and worries a lot of people so the potential for neuroscience to help those with difficulties to learn better is exciting but there are still a lot of ethical and scientific issues to explore,' says Professor Cohen Kadosh who also worked with Oxford neuroethicists to deal with such problems.

'It is also important to explore its impact on children from different educational and cultural backgrounds, and children with other developmental conditions, such as dyslexia or ADHD. This would allow a better understanding if such approach could be used in schools to help those with learning difficulties in the future.'

This type of study was first to take place in a school environment. Professor Cohen Kadosh said he hopes this trial will encourage other schools to take part in future neuroscientific research, but warned that members of the public should not try to use tRNS on themselves or on children.

'The trial was carried out by experts with years of training in brain stimulation and expertise in mathematical cognition, who did careful medical and safety screening before deciding if a child could take part in the study,' he said.

'We urge people not to buy devices claimed to achieve these or similar results -- do not try this at home!'

What this study shows:

• Indicators that children who received brain stimulation during numerical training showed better learning compared to those in the sham stimulation group.
• Hints that improvement induced by tRNS was associated with improvement in a standardized diagnostic mathematical test
• No children showed or reported minor or major side-effects
• Effects of brain stimulation during numerical training was specific to numerical abilities
•  

We should be aware that:

• ·      Brain stimulation at that stage should NOT be used in children with learning difficulties beyond experiments conducted by scientists.
• ·      NOT all children will benefit from this approach: We need to see a trial on a large sample size and heterogeneous population, and know if cognitive and neural factors could predict who would benefit from this approach.
• ·      This approach may NOT be safe for use in all children: There are conditions that make brain stimulation unsafe, and children need to have careful health and safety screening before receiving brain stimulation.
• ·      We should NOT use brain stimulation to enhance performance in typically developing children: We do not know its effect on children with typical abilities, and such approach in our view pose ethical problem, as there is a different benefit/risk ratio tRNS itself is NOT the only important factor: it must be combined with numerical training. Actually the numerical training game showed an improvement on maths performance that lasted 4 months later.
• ·      tRNS is NOT ready to be used as an intervention tool.

https://www.sciencedaily.com/releases/2017/08/170829124756.htm

Depression affects the brains of males and females differently

New findings suggest that adolescent girls and boys might experience depression differently and that sex-specific treatments could be beneficial for adolescents

July 11, 2017

Science Daily/Frontiers

Depressed adolescents were exposed to happy or sad words and their brains imaged. Through this study, researchers found that depression has different effects on the brain activity of male and female patients in certain brain regions. The findings suggest that adolescent girls and boys may experience depression differently and that sex-specific treatments might be beneficial for adolescents.

When researchers in the UK exposed depressed adolescents to happy or sad words and imaged their brains, they found that depression has different effects on the brain activity of male and female patients in certain brain regions. The findings suggest that adolescent girls and boys might experience depression differently and that sex-specific treatments could be beneficial for adolescents.

Men and women appear to suffer from depression differently, and this is particularly striking in adolescents. By 15 years of age, girls are twice as likely to suffer from depression as boys. There are various possible reasons for this, including body image issues, hormonal fluctuations and genetic factors, where girls are more at risk of inheriting depression. However, differences between the sexes don't just involve the risk of experiencing depression, but also how the disorder manifests and its consequences.

"Men are more liable to suffer from persistent depression, whereas in women depression tends to be more episodic," explains Jie-Yu Chuang, a researcher at the University of Cambridge, and an author on the study, which was recently published in Frontiers in Psychiatry. "Compared with women, depressed men are also more likely to suffer serious consequences from their depression, such as substance abuse and suicide." Despite this, so far, most researchers have focused on depression in women, likely because it is more common.

This motivated Chuang and her colleagues to carry out this latest study to find differences between depressed men and women. They recruited adolescent volunteers for the study, who were aged between 11 and 18 years. This included 82 female and 24 male patients who suffered from depression, and 24 female and 10 male healthy volunteers. The researchers imaged the adolescents' brains using magnetic resonance imaging, while flashing happy, sad or neutral words on a screen in a specific order.

The volunteers pressed a button when certain types of words appeared and did not press the button when others appeared, and the researchers measured their brain activity throughout the experiment. When the researchers flashed certain combinations of words on the screen, they noticed that depression affects brain activity differently between boys and girls in brain regions such as the supramarginal gyrus and posterior cingulate.

So, what do these results mean? "Our finding suggests that early in adolescence, depression might affect the brain differently between boys and girls," explains Chuang. "Sex-specific treatment and prevention strategies for depression should be considered early in adolescence. Hopefully, these early interventions could alter the disease trajectory before things get worse."

The brain regions highlighted in the study have been previously linked to depression, but further work is needed to understand why they are affected differently in depressed boys, and if this is related to how boys experience and handle depression.

Because depression is more common in girls, the researchers were not able to recruit as many boys in this study, and future experiments should compare similar numbers of girls and boys for more representative results. Chuang and her colleagues would like to explore this phenomenon further. "I think it would be great to conduct a large longitudinal study addressing sex differences in depression from adolescence to adulthood."

https://www.sciencedaily.com/releases/2017/07/170711085522.htm

Adequate Sleep Helps Weight Loss

September 17, 2012

Science Daily/Canadian Medical Association Journal

Adequate sleep is an important part of a weight loss plan and should be added to the recommended mix of diet and exercise, states a commentary in CMAJ (Canadian Medical Association Journal).

Although calorie restriction and increased physical activity are recommended for weight loss, there is significant evidence that inadequate sleep is contributing to obesity. Lack of sleep increases the stimulus to consume more food and increases appetite-regulating hormones. “Sleep should be included as part of the lifestyle package that traditionally has focused on diet and physical activity."

"The solution [to weight loss] is not as simple as 'eat less, move more, sleep more,'" write Drs. Jean-Phillippe Chaput, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario and Angelo Tremblay, Laval University, Québec, Quebec.

"However, an accumulating body of evidence suggests that sleeping habits should not be overlooked when prescribing a weight-reduction program to a patient with obesity. Sleep should be included as part of the lifestyle package that traditionally has focused on diet and physical activity."

http://www.sciencedaily.com/releases/2012/09/120917123926.htm

Living against the clock; Does loss of daily rhythms cause obesity?

August 29, 2012

Science Daily/Wiley

When Thomas Edison tested the first light bulb in 1879, he could never have imagined that this invention could one day contribute to a global obesity epidemic. Electric light allows us to work, rest and play at all hours of the day, and a new article suggests that this might have serious consequences for our health and for our waistlines.

Daily or "circadian" rhythms including the sleep wake cycle, and rhythms in hormone release are controlled by a molecular clock that is present in every cell of the human body. This human clock has its own inbuilt, default rhythm of almost exactly 24 hours that allows it to stay finely tuned to the daily cycle generated by the rotation of Earth. This beautiful symmetry between the human clock and the daily cycle of Earth's rotation is disrupted by exposure to artificial light cycles, and by irregular meal, work and sleep times. This mismatch between the natural circadian rhythms of our bodies and the environment is called "circadian desynchrony."

The paper, by Dr. Cathy Wyse, working in the chronobiology research group at the University of Aberdeen, focuses on how the human clock struggles to stay in tune with the irregular meal, sleep and work schedules of the developed world, and how this might influence health and even cause obesity.

"Electric light allowed humans to override an ancient synchronization between the rhythm of the human clock and the environment, and over the last century, daily rhythms in meal, sleep and working times have gradually disappeared from our lives," said Wyse. "The human clock struggles to remain tuned to our highly irregular lifestyles, and I believe that this causes metabolic and other health problems, and makes us more likely to become obese."

"Studies in microbes, plants and animals have shown that synchronization of the internal clock with environmental rhythms is important for health and survival, and it is highly likely that this is true in humans as well."

The human clock is controlled by our genes, and the research also suggests that some people may be more at risk of the effects of circadian desynchrony than others. For example, humans originating from Equatorial regions may have clocks that are very regular, which might be more sensitive to the effects of circadian desynchrony.

Shiftwork, artificial light and the 24-hour lifestyle of the developed world mean that circadian desynchrony is now an inevitable part of 21st century life. Nevertheless, we can help to maintain healthy circadian rhythms by keeping regular meal times, uninterrupted night-time sleep in complete darkness, and by getting plenty of sunlight during daylight hours.

Dr. Wyse believes that circadian desynchrony affects human health by disrupting the systems in the brain that regulate metabolism, leading to an increased likelihood of developing obesity and diabetes.

"The reason for the relatively sudden increase in global obesity in the developed world seems to be more complicated than simply just diet and physical activity. There are other factors involved, and circadian desynchrony is one that deserves further attention."

"Our 24-hour society has come at the high price of circadian desynchrony," concluded Wyse. "There are many factors driving mankind towards obesity but disrupted circadian rhythms should be considered alongside the usual suspects of diet and exercise."

http://www.sciencedaily.com/releases/2012/08/120829195119.htm

Weight Gain Induced by High-Fat Diet Increases Active-Period Sleep

July 10, 2012

Science Daily/Society for the Study of Ingestive Behavior

Research presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB) finds that prolonged exposure to a high-fat diet reduces the quality of sleep in rats.

Using radio-telemetry, the authors measured 24-hour sleep and wake states after rats consumed a high fat diet for 8 weeks. Compared to rats that consumed a standard laboratory chow, the rats on the high-fat diet slept more but sleep was fragmented. The increased sleep time of the rats on the high-fat diet occurred mainly during the normally active phase of the day, resembling excessive daytime sleepiness observed in obese humans.

According to lead author, Catherine Kotz, "Studies in humans indicate a relationship between sleep quality and obesity. Our previous work in animals shows a link between good quality sleep, resistance to weight gain and increased sensitivity to orexin, a brain chemical important in stabilizing sleep and wake states. The current studies show that after high-fat diet-induced weight gain in rats, sleep quality is poor and orexin sensitivity is decreased. These findings suggest that poor sleep associated with weight gain due to a high-fat diet may be a consequence of reduced orexin sensitivity."

These studies highlight the impact of weight gain on sleep quality and a potential brain mechanism underlying these diet and weight-gain induced changes in sleep behavior.

http://www.sciencedaily.com/releases/2012/07/120710093804.htm

Brain Scans Show Specific Neuronal Response to Junk Food When Sleep-Restricted

June 10, 2012

Science Daily/American Academy of Sleep Medicine

The sight of unhealthy food during a period of sleep restriction activated reward centers in the brain that were less active when participants had adequate sleep, according to a new study using brain scans to better understand the link between sleep restriction and obesity.

Researchers from St. Luke's -- Roosevelt Hospital Center and Columbia University in New York performed functional magnetic resonance imaging (fMRI) on 25 men and women of normal weights while they looked at images of healthy and unhealthy foods. The scans were taken after five nights in which sleep was either restricted to four hours or allowed to continue up to nine hours. Results were compared.

"The same brain regions activated when unhealthy foods were presented were not involved when we presented healthy foods," said Marie-Pierre St-Onge, PhD, the study's principal investigator. "The unhealthy food response was a neuronal pattern specific to restricted sleep. This may suggest greater propensity to succumb to unhealthy foods when one is sleep restricted."

Previous research has shown that restricted sleep leads to increased food consumption in healthy people, and that a self-reported desire for sweet and salty food increases after a period of sleep deprivation. St-Onge said the new study's results provide additional support for a role of short sleep in appetite-modulation and obesity.

"The results suggest that, under restricted sleep, individuals will find unhealthy foods highly salient and rewarding, which may lead to greater consumption of those foods," St-Onge said. "Indeed, food intake data from this same study showed that participants ate more overall and consumed more fat after a period of sleep restriction compared to regular sleep. The brain imaging data provided the neurocognitive basis for those results."

http://www.sciencedaily.com/releases/2012/06/120610151447.htm

With Fat: What's Good or Bad for the Heart, May Be the Same for the Brain

May 18, 2012

Science Daily/Brigham and Women's Hospital

It has been known for years that eating too many foods containing "bad" fats, such as saturated fats or trans fats, isn't healthy for your heart. However, according to new research from Brigham and Women's Hospital (BWH), one "bad" fat -- saturated fat -- was found to be associated with worse overall cognitive function and memory in women over time. By contrast, a "good" fat -- mono-unsaturated fat was associated with better overall cognitive function and memory.

The research team analyzed data from the Women's Health Study -- originally a cohort of nearly 40,000 women, 45 years and older. The researchers focused on data from a subset of 6,000 women, all over the age of 65. The women participated in three cognitive function tests, which were spaced out every two years for an average testing span of four years. These women filled out very detailed food frequency surveys at the start of the Women's Health Study, prior to the cognitive testing.

"When looking at changes in cognitive function, what we found is that the total amount of fat intake did not really matter, but the type of fat did," explained Olivia Okereke, MD, MS, BWH Department of Psychiatry.

Women who consumed the highest amounts of saturated fat, which can come from animal fats such as red meat and butter, compared to those who consumed the lowest amounts, had worse overall cognition and memory over the four years of testing. Women who ate the most of the monounsaturated fats, which can be found in olive oil, had better patterns of cognitive scores over time.

"Our findings have significant public health implications," said Okereke. "Substituting in the good fat in place of the bad fat is a fairly simple dietary modification that could help prevent decline in memory."

Okereke notes that strategies to prevent cognitive decline in older people are particularly important. Even subtle declines in cognitive functioning can lead to higher risk of developing more serious problems, like dementia and Alzheimer disease.

http://www.sciencedaily.com/releases/2012/05/120518081358.htm

When You Eat Matters, Not Just What You Eat

May 17, 2012

Science Daily/Cell Press

When it comes to weight gain, when you eat might be at least as important as what you eat. That's the conclusion of a study reported in the Cell Press journal Cell Metabolism published early online on May 17th.

When mice on a high-fat diet are restricted to eating for eight hours per day, they eat just as much as those who can eat around the clock, yet they are protected against obesity and other metabolic ills, the new study shows. The discovery suggests that the health consequences of a poor diet might result in part from a mismatch between our body clocks and our eating schedules.

"Every organ has a clock," said lead author of the study Satchidananda Panda of the Salk Institute for Biological Studies. That means there are times that our livers, intestines, muscles, and other organs will work at peak efficiency and other times when they are -- more or less -- sleeping.

Those metabolic cycles are critical for processes from cholesterol breakdown to glucose production, and they should be primed to turn on when we eat and back off when we don't, or vice versa. When mice or people eat frequently throughout the day and night, it can throw off those normal metabolic cycles.

"When we eat randomly, those genes aren't on completely or off completely," Panda said. The principle is just like it is with sleep and waking, he explained. If we don't sleep well at night, we aren't completely awake during the day, and we work less efficiently as a consequence.

To find out whether restricted feeding alone -- without a change in calorie intake -- could prevent metabolic disease, Panda's team fed mice either a standard or high-fat diet with one of two types of food access: ad lib feeding or restricted access.

The time-restricted mice on a high-fat diet were protected from the adverse effects of a high-fat diet and showed improvements in their metabolic and physiological rhythms. They gained less weight and suffered less liver damage. The mice also had lower levels of inflammation, among other benefits.

Panda says there is reason to think our eating patterns have changed in recent years, as many people have greater access to food and reasons to stay up into the night, even if just to watch TV. And when people are awake, they tend to snack.

The findings suggest that restricted meal times might be an underappreciated lifestyle change to help people keep off the pounds. At the very least, the new evidence suggests that this is a factor in the obesity epidemic that should be given more careful consideration.

http://www.sciencedaily.com/releases/2012/05/120517132057.htm

Feeling Tired? 'Social Jetlag' Poses Obesity Health Hazard

May 10, 2012

Science Daily/Cell Press

Social jetlag -- a syndrome related to the mismatch between the body's internal clock and the realities of our daily schedules -- does more than make us sleepy. It is also contributing to the growing tide of obesity, according to a large-scale epidemiological study reported online on May 10 in Current Biology, a Cell Press publication.

"We have identified a syndrome in modern society that has not been recognized until recently," said Till Roenneberg of the University of Munich. "It concerns an increasing discrepancy between the daily timing of the physiological clock and the social clock. As a result of this social jetlag, people are chronically sleep-deprived. They are also more likely to smoke and drink more alcohol and caffeine. Now, we show that social jetlag also contributes to obesity; the plot that social jetlag is really bad for our health is thickening.

Their analysis shows that people with more severe social jetlag are also more likely to be overweight. In other words, it appears that living "against the clock" may be a factor contributing to the epidemic of obesity, the researchers say.

"Waking up with an alarm clock is a relatively new facet of our lives," Roenneberg says. "It simply means that we haven't slept enough and this is the reason why we are chronically tired. Good sleep and enough sleep is not a waste of time but a guarantee for better work performance and more fun with friends and family during off-work times." And slimmer waistlines, too.

http://www.sciencedaily.com/releases/2012/05/120510122802.htm

Lack of Sleep May Increase Calorie Consumption

March 14, 2012

Science Daily/American Heart Association

If you don't get enough sleep, you may also eat too much -- and thus be more likely to become obese. That is the findings of researchers who presented their study at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2012 Scientific Sessions.

Participants ate as much as they wanted during the study.

Researchers found:

• ·      The sleep deprived group, who slept one hour and 20 minutes less than the control group each day consumed an average 549 additional calories each day.

• ·      The amount of energy used for activity didn't significantly change between groups, suggesting that those who slept less didn't burn additional calories.

• ·      Lack of sleep was associated with increased leptin levels and decreasing ghrelin -- changes that were more likely a consequence, rather than a cause, of over-eating.

"Sleep deprivation is a growing problem, with 28 percent of adults now reporting that they get six or fewer hours of sleep per night," said Andrew D. Calvin, M.D., M.P.H., co-investigator, cardiology fellow and assistant professor of medicine at the Mayo Clinic.

The researchers noted that while this study suggests sleep deprivation may be an important part and one preventable cause of weight gain and obesity, it was a small study conducted in a hospital's clinical research unit.

http://www.sciencedaily.com/releases/2012/03/120314170456.htm

Obesity, Depression Found to Be Root Causes of Daytime Sleepiness

June 13, 2012

Science Daily/American Academy of Sleep Medicine

Three new studies conclude that obesity and depression are the main culprits making Americans excessively sleepy while awake. Researchers examined a random population sample of 1,741 adults and determined that obesity and emotional stress are the main causes of an "epidemic" of sleepiness and fatigue plaguing the country. Insufficient sleep and obstructive sleep apnea also play a role; both have been linked to high blood pressure, heart disease, stroke, depression, diabetes, obesity and accidents.

Wake up, America, and lose some weight -- it's keeping you tired and prone to accidents. Three studies being presented June 13 at sleep 2012 conclude that obesity and depression are the two main culprits making us excessively sleepy while awake.

Researchers at Penn State examined a random population sample of 1,741 adults and determined that obesity and emotional stress are the main causes of the current "epidemic" of sleepiness and fatigue plaguing the country. Insufficient sleep and obstructive sleep apnea also play a role; both have been linked to high blood pressure, heart disease, stroke, depression, diabetes, obesity and accidents.

"The 'epidemic' of sleepiness parallels an 'epidemic' of obesity and psychosocial stress," said Alexandros Vgontzas, MD, the principal investigator for the three studies. "Weight loss, depression and sleep disorders should be our priorities in terms of preventing the medical complications and public safety hazards associated with this excessive sleepiness."

In the Penn State cohort study, 222 adults reporting excessive daytime sleepiness (EDS) were followed up 7½ years later. For those whose EDS persisted, weight gain was the strongest predicting factor. "In fact, our results showed that in individuals who lost weight, excessive sleepiness improved," Vgontzas said.

Adults from that same cohort who developed EDS within the 7½-year span also were studied. The results show for the first time that depression and obesity are the strongest risk factors for new-onset excessive sleepiness. The third study, of a group of 103 research volunteers, determined once again that depression and obesity were the best predictors for EDS.

"The primary finding connecting our three studies are that depression and obesity are the main risk factors for both new-onset and persistent excessive sleepiness," Vgontzas said.

In the Penn State cohort study, the rate of new-onset excessive sleepiness was 8 percent, and the rate of persistent daytime sleepiness was 38 percent. Like insufficient sleep and obstructive sleep apnea, EDS also is associated with significant health risks and on-the-job accidents.

http://www.sciencedaily.com/releases/2012/06/120613091037.htm

Obesity and the Biological Clock: When Times Are out of Joint

May 10, 2012

Science Daily/Ludwig-Maximilians-Universitaet Muenchen (LMU)

Urgent appointments, tight work timetables and hectic social schedules structure modern life, and they very often clash with our intrinsic biological rhythms. The discrepancy results in so-called social jetlag, which can damage one's health. Among other effects, it can contribute to the development of obesity, as a new LMU study shows.

"Our surveys suggest that in Western societies two thirds of the population are burdened with a significant discrepancy between their internal time and the demands imposed by school and work schedules and leisure stress," says LMU chronobiologist Professor Till Roenneberg, who coined the term "social jetlag" to describe the phenomenon. If the rhythms dictated by our lifestyles are persistently out of phase with our biological clock, the risk of illness, such as high blood pressure and even cancer, rises.

Tired -- around the clock A team of researchers led by Roenneberg has now shown that social jetlag also contributes to another growing health problem, particularly in countries with a Western lifestyle -- obesity. Individuals who are overweight are at increased risk for serious metabolic diseases, such as diabetes. Many factors, in addition to excessive consumption of energy-rich foods, play a role in the development of obesity, and one of them is a lack of sleep. In persons who get too little sleep, the perception of hunger is perturbed, often leading to overeating.

And it is not just sleep duration that is important here. The LMU team has also found that social jetlag shows a significant association with increased body-mass index (BMI). The BMI, which is based on a quantitative relationship between weight and height, is used as a measure of body fat, and varies depending on age and sex.

Individuals with BMIs above the normal range are regarded as being overweight or obese. The results of the new study strongly indicate that a lifestyle that conflicts with our internal physiological rhythms can promote the development of obesity.

Moreover, it appears that the incidence of social jetlag is itself increasing, perhaps as a consequence of a general reduction in sleep duration."The ongoing debate on the usefulness of daylight-saving time (DST) should take note of our findings," remarks Roenneberg. "Just like conventional school and work schedules, DST disrupts our biological clock and subjects us to more social jetlag with all its consequences."

http://www.sciencedaily.com/releases/2012/05/120510132637.htm

New Research Explains How Proper Sleep is Important for Healthy Weight

May 7, 2012

Science Daily/Federation of American Societies for Experimental Biology

If you're counting calories to lose weight, that may be only part of the weight loss equation says a new research report published online in The FASEB Journal. In the report, French scientists show that impairments to a gene known to be responsible for our internal body clocks, called "Rev-Erb alpha," leads to excessive weight gain and related health problems. This provides new insights into the importance of proper alignment between the body's internal timing and natural environmental light cycles to prevent or limit excessive weight gain and the problems this weight gain causes.

According to Etienne Challet, Ph.D., a researcher involved in the work from the Department of Neurobiology of Rhythms at the Institute of Cellular and Integrative Neurosciences at the University of Strasbourg in Pascal, France,

"It is now clear that impairment of daily rhythms such as shift-work, exposure to artificial lighting, or jet-lag has multiple adverse effects on human health, every effort should be made to maintain or restore normal temporal organization and to avoid potentially disruptive behaviors such as nocturnal meals or light exposure at night."

To make this discovery, Challet and colleagues studied two groups of mice. One group was normal and the other group lacked the Rev-Erb alpha gene. In the mice lacking the Rev-Erb alpha gene, it was determined that they became obese and hyperglycaemic even if they ate the same quantity of food at the same time as normal mice.

Further scientific investigation showed that when the Rev-Erb alpha-deficient mice were compared to the normal mice, there was a major difference in the way Rev-Erb alpha-deficient mice metabolized the food they ate. The Rev-Erb alpha deficient mice created much more fat than the normal mice, and this occurred specifically during the feeding period. Additionally, the Rev-Erb-alpha deficient mice relied less on carbohydrate stores when at rest.

http://www.sciencedaily.com/releases/2012/05/120507113734.htm