Nikki Cameron has a message for the pupils of Glasgow. If they take heroin, it will kill them eventually, she says. Ditto, if they smoke or drink too much alcohol. But, if they suffer sleep deprivation, this is a form of torture, she tells them. "Two weeks without sleep will leave you dead," she says. "You have to take the message about lack of sleep as seriously as other dangerous habits."
These unique sleep lessons are being piloted by the charity Sleep Scotland with funding from Childline, in four secondary schools in Scotland's largest city where the sleep professionals are encountering a large number of yawning children with bags under their eyes who can't concentrate in class. More than half of the pupils themselves admit to not getting enough sleep at night.
The sleep specialists would like to see the scheme expand so that every schoolchild has the chance to learn how to benefit from better sleep, which research has shown can improve grades, mental health and sports performance.
"We see the provision of sleep counsellors as absolutely vital to the promotion of good sleep in children," says Cameron. "The teenagers are telling us that they would prefer to see an expert in a one-to-one session to talk about their sleep problems."
The feedback that Sleep Scotland has received in a survey of Glasgow pupils points to an epidemic of poor sleep. Two-thirds of children are not getting the nine hours sleep required to reach their full potential. They need to be in bed between 11 and 12.30 at night and get up between 7 and 8.30 am – but they are not.
What are they doing late into the night when they should be getting their nine hours of shut-eye? Some are using computers but the majority are watching stimulating late night American TV dramas in their rooms. Cameron is not surprised by the figures: "These results are exactly what we expected and mirror research carried out in the US," she says.
"This is not a reflection on our schools or our teaching, but simply on the society we have created where we have fostered the macho idea that it is a positive to survive on five hours sleep."
And according to American research, the teenagers who are having fewer than five hours have a 71 per cent higher risk of depression than those who sleep eight hours. Ms Cameron describes the descent into depression as a vicious cycle. "After a night of disrupted sleep, the teenager will feel it the next day but, if it goes on longer, then they are building sleep debt and it becomes really difficult to get that sleep back if you don't make any real changes.
"There will be an immediate effect on concentration and they will feel tired and unwell, the temper will go and in a few days they will start to feel flat and down."
A leading child sleep disorder specialist Cathy Hill explains that despite these depressing figures the pattern can be altered, as sleep is learned behaviour. The adolescents must first be taught to value sleep.
"The difficulty for sleep across the board is that it is undervalued because it is an unconscious private activity which happens in the hours of darkness," says Hill who is a lecturer in child health at Southampton University.
"Not only is it not given the value in society it should have, the converse is true as we celebrate people who can manage on four hours, when in fact the less we have during night-time plays a major factor on our productivity."
Teenagers are becoming particularly sleep deprived because they tend to want to go to sleep later as they get older, according to Hill. In addition they have a large number of distractions in their bedrooms – computers, games, mobile phones and other equipment that they are not switching off until late. At the same time they still have to get up for school. "And so they become chronically sleep deprived; the litmus test is that they are all sleeping in at the weekend."
But lack of sleep doesn't simply affect your ability to learn, it is also linked to obesity. Research shows you are three times more likely to be obese if you have less than 10 hours sleep a night in middle childhood. For each additional hour of sleep you get, you decrease your risk of obesity by nine per cent, according to Hill. "There's a link between the secretion of hormones which controls appetite and sleep," she says. "If you think about when you are really, really tired, you crave carbohydrates.
"If we could just get the children of the nation to bed at night we would have brighter, smarter children and we would help reduce the risk of obesity."
Kyle Thornton has decided to follow this advice. A typical teenager, he was surviving on six hours a night until the sleep classes at Bellahouston Academy made him rethink his lifestyle. "Sleep had never been a priority," he says. "I would stay up until after midnight watching TV or on the PlayStation or computer.
"I always felt knackered but just accepted that feeling tired was the norm." It was the link between obesity and sleep that struck a chord with Kyle. "The lessons got me thinking about sleep, especially the facts she told us in class. As I am a wee bit overweight the thing that stood out for me was that your body actually burns calories when you are sleeping, as well as repairing itself and this is when learning takes place.
"When I found out I was more likely to get a higher grade with a good night's sleep, I thought I should try to get the best out of myself and aim for nine hours a night."
In the two weeks that Kyle has started getting the required hours of sleep, he has noticed a major change in how he feels. "After the first night, I felt immediately better and since then I feel I am lasting longer in the school day and am less irritable in the morning," he says. "Obviously, it is too early to say whether I have improved academically but I do feel I'm concentrating better in class."
While the emotional, behavioural and academic problems associated with reduced sleep can be remedied with a little rigour, the reality is more daunting. Denise Boyle only sleeps five hours most nights, as she spends time in bed contacting her friends online. She knows lack of sleep is making her grumpy, affecting her academic prospects and means she can't stop yawning in class, but she can't break her nocturnal habits. "I can't not use the computer before I go to sleep," she says. "I need to know what my friends are saying."