DR. MOHLER: Does the full moon really affect behavior? | PostIndependent.com

DR. MOHLER: Does the full moon really affect behavior?

Phil Mohler, M.D.
Free Press Health Columnist

Talk to any experienced obstetrician nurse, veteran police officer, or grey-haired emergency room doc and they will all agree with Shakespeare’s Othello:

“It is the very error of the moon,

She comes more near the earth

than she was wont,

And makes men mad.” (and makes women go into labor…)

The concept that the full moon influences human behavior has been around since ancient Romans worshipped the moon goddess, Luna. The associated ideas of lunacy (periodic insanity, folly) and lunatic (someone absurd, crazy or mad) were born.

The theory was that prior to modern lighting, the moon was a significant source of nighttime illumination. The full moon kept people awake, and being sleep deprived, they developed seizures, agitation and even madness. Sound silly? Not really, as we know from modern sleep studies that deprivation of sleep for even one night can precipitate an acute agitated state in some people. Others have postulated that just as the moon affects the ocean tides, it may also affect the water content of the brain, thus disrupting our behavior. Not likely!

In 2010, a poll in the U.S. showed that 50% of Americans believe in the power of the full moon in changing behavior. However, when obstetricians, psychiatrists (and their patients), police officers, nursing home attendants and ER personnel were queried, 70%-80% thought that the full moon predicted a difficult night ahead. At times, some ER nurses have demanded extra “full moon pay” and in England some police departments have added extra officers on full moon nights in an effort to cope with presumed higher crime rates.

Dozens of scientific studies over the last century have shown no relationship of lunar cycles with bizarre behaviors, seizures, mental health conditions or birth rates. But now, a study from Australia sheds new light! These authors found that when they studied violent and severe behaviors, twice as many patients presented during the full moon than during any other lunar phase.


I dreaded being on call during full moons, particularly OB call.

This column was written on the evening of Saturday, Oct. 19, 2013. Check your almanac.

Dr. Mohler has practiced family medicine in Grand Junction for 38 years. He has a particular interest in pharmaceutical education. Phil works part-time for both Primary Care Partners and Rocky Mountain Health Plans. Email him at pjmohler@bresnan.net.

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