Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It’s said that crime rates increase and emergency rooms are much busier during the full moon. (Plus, there’s that whole werewolf thing!) Why would this be? The reasoning is that the Moon, which affects the ocean’s tides, probably exerts a similar effect on us, because the human body is made mostly of water.
This belief that the moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it’s true—that a team of researchers at Université Laval’s School of Psychology in Canada decided to find out if mental illness and the phases of the moon are linked.
To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients complained of chest pains; doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.
When the researchers compared the time of the visits to the phases of the moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception—in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," says Dr. Geneviève Belleville, who directed the team of researchers. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."
So rest easy (or maybe not): If people are acting crazy during the full moon, it’s likely because they’re just that crazy all the time.