In 2005, a woman showed up at Emory University's sleep center in
Atlanta complaining of being sleepy just about every moment of
every day. She slept for 14, then 16, then 18 hours a night, but
still woke up feeling drowsy. Doctors had prescribed her
stimulants, which worked for a bit. But when they wore off, she
would go on a sleeping binge, becoming unarousable for days at a
time. Her diagnosis? Hypersomnia, a rare and debilitating
condition in which people sleep excessively, are extremely
drowsy while awake, and respond poorly to existing anti-sleep
treatments. The condition can make people unable to work or
maintain relationships. When the woman showed up at the sleep
center, researchers did a range of tests and finally took
samples of her cerebrospinal fluid. They discovered it had some
unusual properties. Namely, something in it caused GABA, the
main neurotransmitter molecule responsible for reducing the
activity of brain cells, to have an outsized effect. In essence,
a mystery molecule appeared to be wo