It might be the moon's fault you're sleeping so poorly.
That's the conclusion of a small new study in the journal Current Biology, which showed that the lunar cycle really does seem to affect how well we sleep.
Specifically, researchers from the Psychiatric Hospital of the University of Baesel found that people have 30 percent less deep-sleep-related brain activity, get 20 fewer minutes of sleep a night, and take an extra five minutes to fall asleep around a full moon.
The findings are based on 33 people who were monitored as they slept in a lab.
"The lunar cycle seems to influence human sleep, even when one does not 'see' the moon and is not aware of the actual moon phase," study researcher Christian Cajochen said in a statement.
Researchers noted that the relationship between sleep and the full moon may have something to do with the moon's role in synchronization of human reproductive behaviors.
TIME magazine explained how it is that the moon could have an effect on sleep, even when the study participants were indoors (away from the sight of the moon):
Rather, the answer is simply that we, like every other species on Earth, evolved on a particular planet with a particular set of astronomical cycles -- day and night, full moons and less full -- and our circadian systems adapted. It’s hard to say where the internal clock is in, say, a flowering plant, but in humans, it’s likely in the suprachiasmatic nuclei, a tiny region of the brain near the optic nerve involved in the production of melatonin, certain neurotransmitters and other time-keeping chemicals, all in a rhythm consistent with both its terrestrial and cosmic surroundings. Physically, human beings may be creatures of just this world, but our brains -- and our behavior -- appear to belong to two.
This isn't the first health behavior linked to the moon. LiveScience reported on a number of studies around the moon's effects back in 2009, including ones showing links between a full moon and pet injuries, women's menstruation and sleep deprivation.