Brain experiments and behavioural studies show that this is an unhealthy habit, for memory, cognition and mood at every age. Sleep, in such short supply for today’s adolescents, may be especially important for development during puberty.
And the quality of sleep is a key factor: A Harvard University study released in September found the hormone that triggers ovulation in girls and testosterone production in boys was most actively released by the brain during deep sleep. In a recent experiment at Brock University in St. Catharines, Ont., sleep-deprived students were found to have suppressed levels of testosterone, and, compared with a control group, were less motivated to challenge a cheater in a card game.
“You are effectively blunted to do anything inspirational or active, you don’t really care about anything,” says psychology professor Kimberly Cote, who led the study. In another experiment, Brock researchers found that sleepy subjects took significantly longer to notice errors in a computer test than a well-rested control group.
Neuroimaging experiments are also unravelling the stages of sleep – to unlock the role it plays in consolidating memory and controlling behaviour.
At the University of Montreal, researcher Stuart Fogel is conducting studies in which subjects sleep in a magnetic-resonance imaging (MRI) machine after learning a new memory task to see what parts of the brain are active as they rest. (In another experiment, he found that young adults who napped after learning a task performed it better after waking than those who stayed awake.)
Research elsewhere is exploring how sleep is different for people with mental disorders such as schizophrenia. Several papers published last year used MRI scans to show that, when people were short on sleep, the higher-thinking region of the brain that dictates food choices was impaired, leading them to crave sweeter and saltier tastes. Research is also revealing the potential long-term implications of poor sleep – another recent study found a link between sleep and insulin resistance in teenagers, which could affect the risk of diabetes later in life.
And yet a little more sleep goes a long way. In one of Reut Gruber’s recent studies, giving just 27 minutes more sleep to children who are 7 to 11 shows improvements in their emotional behaviour in school, and a significant drop in reported sleepiness. (Dr. Gruber reports similar findings with children with attention-deficit disorders.)
As for Kush Thaker, he has accepted his sleepy adolescence – dozing off in morning classes, catnapping (along with many of his peers) during study period and resorting to the occasional Red Bull, although lately, he is more likely to try water – “drinking, splashing, whatever works.”
Mathew Pilon, 17, a Grade 12 student in Port Colborne, Ont., quips that, unless “the Earth’s rotation slows drastically somehow, … I’m stuck with drowsy morning and sleepless nights.”
The problem is that those drowsy mornings and sleepless nights add up to a lifetime of sleep deficits.
And even if science is still struggling to assess whether the end result will be good or bad, “the impact of poor sleep on society is rather under-appreciated,” a tactful Stuart Fogel says.