Sleep Gone Awry
Researchers inch closer to causes, cures for insomnia, narcolepsy
If Ben Franklin had been able to live by his own advice, he might have been even healthier, wealthier and wiser. But he was a notorious insomniac, rumored to have been such a poor sleeper that he required two beds so he could always crawl into one with cool sheets when he couldn’t sleep. Getting a good night’s sleep turned out to be more difficult than taming lightning, heating houses or designing bifocal specs.
Today millions of people afflicted by sleep disorders know how Franklin felt. Some people can’t fall asleep even when they’re exhausted. Yet other people fall asleep when they should be wide awake. Although sleep disorders take many different forms, they do have one thing in common: The more researchers learn, the more they have left to figure out. Sleep problems present a constellation of symptoms, trigger overlapping diagnoses and divulge no clear causes.
“We always feel like we’re one step away from getting all of the answers,” says Adi Aran of Stanford University, “but I really believe that in the next decade we will understand much more about sleep disorders.”
Already, some recent advances have brought scientists closer to discerning the ultimate causes of such disorders, even suggesting possible treatments. Masashi Yanagisawa of the University of Texas Southwestern Medical Center at Dallas believes researchers are poised to “crack open the black box of sleep regulation.”
Glimpses into that black box suggest that insomnia stems from overactive body systems that conspire to overtake a perfectly functional sleep system. Two reports find that one measure of arousal, blood pressure, is elevated in people with insomnia even while they are asleep.
Other glimpses come from studies of narcolepsy. Scientists have known for almost a decade that narcolepsy is caused by a dearth of a brain communication chemical called orexin. But researchers are still struggling to explain why the neurons that produce orexin are lost in the brains of people with narcolepsy. New evidence implicates a malfunction of the immune system as a likely culprit.
Understanding what goes wrong in sleep disorders such as narcolepsy and insomnia may lead to more targeted treatments. Instead of flooding an insomniac’s brain with a general depressant, clinicians may one day specifically target particular overactive brain regions. Rather than giving people with narcolepsy stimulants that rev up the entire body, preventive measures may halt neuron death before narcolepsy sets in. More generally, understanding these disorders may help researchers create a more complete picture of normal sleep and normal wakefulness, and how bodies and brains transition between the two.
Sleepless nights