What we do know is what happens to a person when they can’t sleep. In extreme cases, like with fatal familial insomnia, a genetic disorder that comes on in middle age, a total lack of sleep can kill someone in about a year. But for those who are merely not getting as much sleep as they need, doctors find decreased levels of growth hormone and increased levels of cortisol. After a week of sleep deprivation, a previously healthy man or woman can become insulin resistant. Their memory, ability for creative problem solving, motivation to complete tasks, and learning potential all suffer. Long-term insomnia puts you at a greater risk for osteoporosis, heart disease, weight gain, and diabetes. Knowing all of this, by the way, does nothing to help soothe you when you wake up at 3 a.m. again.

I’ve tried to write several poems about insomnia, but my efforts all pale to Plath’s entry on the subject, aptly titled “Insomniac:”

Nightlong, in the granite yard, invisible cats
Have been howling like women, or damaged instruments.
Already he can feel daylight, his white disease,
Creeping up with her hatful of trivial repetitions.
The city is a map of cheerful twitters now,
And everywhere people, eyes mica-silver and blank,
Are riding to work in rows, as if recently brainwashed.