Students who think that a long sleep in on the day of a test is better for their grades may be shocked to find out that added rest could actually hurt a teen’s marks, meaning they ought to spend less time in their double or single bed prior to doing their exam.

A new study published in the Eastern Economics Journal discovered that more conventional wisdom may not necessarily be correct. Despite guidelines in the US – where the research was carried out – recommend nine hours of sleep a night, it may in fact be way too much.

It was discovered by Eric Eide and Mark Showalter – economics professors at Brigham Young University – that students between 15 and 18 ought to target seven hours a night, following analysis of sleep and standardized test scores that existed before the study.

The study also went on to show that the amount of sleep necessary for better grades generally declined with age – 16-year-olds were found to need around two hours less than ten-year-olds.

Individuals who have sleep problems may be at a greater risk of suffering from memory deterioration like Alzheimer’s disease later down the line, according to new research.

In a study of 100 participants conducted by the Washington University School of Medicine, it was revealed that individuals who woke more than five times in an hour each night while in bed were at a higher risk of developing a build-up of amyloid plaques in the brain – a common symptom of Alzheimer’s.

Though the evidence sheds some light on the relationship between our sleep quality and memory and has the potential to help prevent future cases of Alzheimer’s, lead author of the study Yo-EL Ju from the school explained that the research is not yet conclusive.

He commented: “We need longer term studies to determine whether disrupted sleep leads to amyloid plaques, or whether brain changes in early Alzheimer’s disease lead to changes in sleep.”

Nine per cent of the population of Australia – more specifically, more than 1.5 million adults living in the country – suffer from sleep disorders. New research has calculated that the overall cost of these conditions to the Australian economy is more $5 billion (£3.4 billion) a year in direct and indirect costs.

A study conducted by Deloitte Access Economics calculated the collective effects of Australians who toss and turn in their single beds as a result of sleep problems, and the losses caused through productivity, absenteeism and poor work performance.

Conditions like sleep apnoea, insomnia and restless leg syndrome were found to have a total direct health cost of around $800 million (£542 million) a year and indirect costs, including workplace accidents and productivity losses, a total of around $4.3 billion (£2.9 billion).

In an interview with ABC News, director of the West Australian Sleep Disorders Research Institute Professor David Hillman said: “What these conditions have in common is that they disrupt sleep and cause daytime symptoms: tiredness, lethargy and really suboptimal brain function.

“I’ve dealt with people who actually believe they can train themselves to sleep less – that’s simply not possible. Sleep is a physiological need that has to be met and if you don’t meet it you can very readily measure the effects on brain function.”

Past studies have suggested that eating just before you crawl into your double bed isn’t good for your body, but a new study has claimed to shed more light on the relationship between our appetite for food and quality of sleep.

A study conducted by researchers from the Department of Neuroscience at Uppsala University in Sweden (published January 18th) found that not getting enough sleep can actually increase an individual’s appetite and, as a result, their risk of obesity down the line.

The researchers examined the brains of 12 normal-weight males, using a magnetic imaging technique. They showed them pictures of various foods after a normal night of sleep and once again after a sleepless night.

The regions of the brain which alert us to feeling hungry were found to be influenced by acute sleep loss – with more activity taking place in these areas when respondents were tired.

Christian Benedict, a lead researcher of the study, urged individuals “to sleep about eight hours every night to maintain a stable and healthy body weight”.

Insomnia can lead to “substantial long-term effects” on sufferers’ physical and mental health, according to new research, meaning it has never been more important for doctors to question patients who struggle to sleep in their divan beds in a bid to get to the root of their problem.

In a review published by the Lancet, it was revealed that 70 per cent of insomnia sufferers continue to experience their symptoms a year down the line, while half live with the problem three years later. As a result, they are left open to conditions like high blood pressure, diabetes and depression.

The lead authors of the review – Dr Charles Morin from the Université Laval in Québec City and Ruth Benca from the University of Wisconsin in Madison – emphasised the need for routine questioning of patients about their sleep problems.

“There is an urgent need for more public education about sleep and broader dissemination of evidence-based therapies for insomnia, and education and training to prepare health-practitioners to attend and treat insomnia complaints according to clinical guidelines.”

It is a common practice for people to sleep on a problem to gain perspective on their situation the following morning. However, new research has claimed that doing so could actually make matters worse.

In a study by the University of Massachusetts Amherst, in which 106 young adults were exposed to both upsetting and pleasurable pictures and their reactions examined before and after sleep, it was found that sleeping on a problem in our wooden beds could keep unpleasant memories fresh in our minds upon waking.

Lead author of the study Dr Rebecca Spencer explained that the findings relate to the human body’s process of evolution, where the retention of painful memories would teach our ancestors not to repeat the actions that resulted in these feelings in the first place.

She said of the research: “Some previous studies have looked at just memory itself, not how emotional reactivity changes. When they looked at how our responsiveness changes they have a different and limited measure.

“There have been a few studies which look at one or the other but this is the first to look at them side by side.”

There is a longstanding debate over which is better for our babies: breast or bottle-feeding. However, new findings suggest that in terms of sleep quality and the happiness of our little ones, the latter may be better.

In a study of more than 300 three-month-old British infants, conducted by the Medical Research Council Epidemiology Unit in Cambridge, it was revealed that breast-fed babies smiled and laughed less and cried more, and it was harder to get them to drift off to sleep in their children’s bed.

The mothers of these infants were asked simple questions about their child’s behaviour when being washed, dress and put to bed and their answers were compared. The researchers claimed that the irritability of breast-fed babies found was not symptomatic of the child’s stress or hunger, but a natural reaction to being apart from its mother.

Professor Nick Wareham, director of the MRC Epidemiology Unit, called for more research into the area to help boost breastfeeding numbers, as only three-quarters of new mums breastfeed their child in the UK today.

Parents are typically aware that sufficient sleep is an essential ingredient for the healthy growth and development of their toddlers. However, new research has revealed that daytime naps are also an important part of a young child’s upbringing, and failure to have enough of them could result in an unhappy child.

In a study conducted by the University of Colorado Boulder, published this month (January 3rd), the emotional expressions of healthy, nap-deprived toddlers were studied an hour after they missed their scheduled nap. Then were studied again on a different day after they were allowed their scheduled nap, and the findings were compared.

The results showed that only one nap needs to be missed to impact on the cheerfulness of children aged between two and a half and three years old. Toddlers who didn’t get enough time in their children’s bunk beds exhibited “more anxiety, less joy and interest and a poorer understanding of how to solve problems.”

CU-Boulder assistant and leader of the study Professor Monique LeBourgeois said of the findings: “[I]nsufficient sleep in the form of missing a nap taxes the way toddlers express different feelings, and, over time, may shape their developing emotional brains and put them at risk for lifelong, mood-related problems.”