Do You Suffer from Paradoxical Insomnia?

In this edition of Today in Science, people with this less-understood form of insomnia report that they are awake all night, when they're actually asleep.

This is an abbreviated version of Today in Science, our free daily newsletter that covers the latest cutting edge discoveries in science. Sign up to get the full edition of Today in Science in your inbox every day.

-- Andrea Gawrylewski , Chief Newsletter Editor

Up All Night

People with so-called subjective insomnia (also called paradoxical insomnia) report that they’ve been awake all night, even when the polysomnography, the gold standard for sleep measurement, says they’ve been asleep. Now, scientists have taken more extensive measurements of the condition and found that this type of insomnia involves spurts of arousal–fast brain waves–during rapid eye movement (REM) sleep. The typical “quiescent” state of REM (immersive dream state) dissolves emotional distress that has accumulated throughout the daytime. People who experience interrupted REM never reach a deep state of REM and report poor sleep (though technically they have been sleeping).

Why this matters: Interrupted REM is strongly linked to disorders such as post-traumatic stress disorder (PTSD) and anxiety. If two people experience the same level of trauma, a good sleeper is probably less likely to develop PTSD than someone with disturbed sleep. And those with disturbed sleep are therefore more vulnerable to developing PTSD–a vicious cycle.

What the experts say: "Sound REM sleep is the only state during which the brain has a ‘time-out’ of noradrenaline [norepinephrine],” which is a stress hormone, says Eus van Someren, a sleep scientist at the Netherlands Institute for Neuroscience. “The neurons are not firing anymore, so they don’t release noradrenaline downstream in the brain.”

Sign-up to read the full version of Today in Science, free every workday!