The full moon doesn't make you crazy, study confirms

Dan Joling / AP

A nearly full moon sets over waters of Cook Inlet and a children's whale slippery slide just before sunrise on Tuesday, at Elderberry Park in downtown Anchorage, Alaska. Anchorage's next full moon is Wednesday.

When there's a full moon (like the one Wednesday), there's a tendency to blame some people's strange behavior on it. But a new Canadian study dismisses this popular belief and suggests that more people with psychological problems do not show up at hospital emergency rooms during a full moon.

Researchers found little evidence that the moon's lunar cycles were linked to an increased incidence of mental health concerns. 

In other words, the moon's behavior seems to have no effect on human behavior on planet Earth. Sure, the word "lunatic" derives from the Latin word "luna" for "moon," but science has found little connection between the moon and madness.

Even so, that won't stop some of us from thinking that lunar cycles can influence psychological symptoms. By one estimate, 80 percent of nurses and 64 percent of doctors who work in the emergency department believe it affects patients' mental health.

In the study, which will appear in the journal General Hospital Psychiatry, researchers reviewed medical records from two hospitals in Montreal over a three-year period. They looked at nearly 800 patients who came to the emergency room for unexplained chest pains, meaning doctors aren't sure what caused their heart trouble.

Researchers studied unexplained chest pains because people with this complaint often suffer from many psychological difficulties, including panic attacks, anxiety and mood disorders, and suicidal thoughts.

They also investigated this topic because the research team was already conducting a study on panic attacks and unexplained chest pains. And the emergency department personnel would often make comments, such as "This would be a good night for research because it's a full moon," says study researcher William Foldes-Busque, PhD, an assistant professor of psychology at the University of Quebec in Montreal, Canada. So, experimenters knew some health professionals already had this perception in their heads, but they wanted to see if the idea had any truth to it.

After patients completed a mental health evaluation, scientists then analyzed data to find out if their psychological symptoms revealed any seasonal patterns or lunar phase influence. Researchers were able to determine which one of the moon's four phases -- new moon, first quarter, full moon, or last quarter -- was present on the day each patient came to the emergency room.

The study found that lunar cycle had no influence on the occurrence of psychological problems, such as panic attacks, anxiety and mood disorders, or suicidal thoughts. The only exception was a 32% drop in the frequency of anxiety disorders during the moon's last quarter. 

"We don't know for sure why this happened," says Foldes-Busque.

Other studies have looked at admissions to psychiatric hospitals, calls to crisis hotlines, or homicide rates, and also failed to turn up a link between the moon's illumination and behavior changes. But if you talk to health professionals or police officers, they may think there's more nuttiness and craziness during a full moon. 

It's possible that people are more prone to notice -- and remember -- a full moon, so they may link any strange behaviors they see that day to it. And perhaps when people act odd during other times of the month, they're just considered weird -- no further explanations given.

Foldes-Busque says it's possible the moon affects mental health in other ways. "I've heard that the full moon may affect sleep, mostly because of increased luminosity," he says.

What's his advice for today's full moon? "Don't do anything special or change anything because of it."

Related: 

Do you hear what I hear? Your brain on Christmas music

Coffee helps you see the bright side

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Discuss this post

I think it's just too many Hollywood movies about full moons and psychotic people, monsters attacking, and transformations over the years.Add in books read, and the flood of ideas of how we are affected by the planets with astrology, and people will get all sorts of ideas. Over the decades there have been thousands of movies, videos, games and no wonder these doctors think there is a link. Who wouldn't?

    Reply#1 - Tue Nov 27, 2012 9:37 PM EST

    I have known many tavern/bar owners and everyone of them say they have more problems with patrons during a full moon.

    • 2 votes
    #1.1 - Wed Nov 28, 2012 4:29 PM EST

    Actually, the moon does have an affect on our bodies. (but not necessarily the MIND) We're about 80% water and water is influenced...pulled and pressured. Any changes on one part of the body affects the others. People in danger of a heartattack, stroke, stomach problems often go over the safety edge during a full moon. Maybe the body shift makes some people feel scared, out of control, angry whatever but this absolutely doeas happen and no "study" paid for by anyone is going to change the System Of Nature. We are part of it, not outside watching. We're IN it and have to flow with it as the system demands.

      #1.2 - Wed Nov 28, 2012 5:38 PM EST
      Reply

      So people not checking into hospitals means they don't become affected by Full Moons? I have witnessed it myself by the aggression of drivers during the days leading up to and days of Full Moons. I actually pay attention to it. It's not just a myth. No one is becoming completely nuts, but it does have an impact on decision making.

        Reply#2 - Wed Nov 28, 2012 10:05 AM EST

        I disagree, and apparently, so does the majority of the scientific community.

        From the article:

        It's possible that people are more prone to notice -- and remember -- a full moon, so they may link any strange behaviors they see that day to it.

        People like to see cause and effect.

          #2.1 - Wed Nov 28, 2012 1:36 PM EST
          Reply

          Ask any police dispatcher how crazy it gets up to and including a few days after a Full Moon. It is not that "crazy" people come out and play - it is people do weird and crazy things, i.e., driving agressively, being unruly and generally rude. It is definitely noticeable.

          • 1 vote
          Reply#3 - Wed Nov 28, 2012 10:24 AM EST

          My husband is bipolar, he is more active leading UP to full moon, the day of the moon he usually crashes and sleeps, and then sleeps for days. I can set my watch by the way he cycles.

          • 1 vote
          Reply#4 - Wed Nov 28, 2012 10:25 AM EST

          This is exacly what we saw in the Hospital ER...A few days before, all kinds of body problems would act up in people. But I maintain its a Body issue not a mind issue. People react all different kinds of ways to feeling the body shifts..fear, anger, chaotic. They act out more. The mind is influenced by the body. When your healthy you feel good. Then the Moon is romantic. If your not, you get confused and lash out. And if the weakest part of the body is just waiting to blow, the Chemical, Fluid and pressure shifts give the extra push. Week before Full Moon: expect more acute problems especially heart attacks, TIA, and overdoses, spouse abuse etc. When the full moon hits, every sighs with relief knowing its almost over.(for a month)

            #4.1 - Wed Nov 28, 2012 5:54 PM EST
            Reply

            No, no, no. They looked in the wrong place. Not the Emergency Room, dummies. Go to any psych ward in any institution and study how behaviors change around a full moon. I know psych nurses who can verify that their charges become more agitated, restless, etc. during a full moon.

              Reply#5 - Wed Nov 28, 2012 10:50 AM EST

              Your neighbors were already nuts. The full moon provides better lighting.

              • 2 votes
              Reply#6 - Wed Nov 28, 2012 10:53 AM EST

              They looked at nearly 800 patients who came to the emergency room for unexplained chest pains, meaning doctors aren't sure what caused their heart trouble.

              They loooked at one type of ailment in two hospitals and came up with a conclusion. Wow think they might have been biased going into this? lol.

              And I don't know about anyone else but after a full moon I always wake up with muddy feet and a bloated feeling in my gut.

              • 1 vote
              Reply#7 - Wed Nov 28, 2012 11:02 AM EST

              Most anyone who works in a hospital will tell you that a Full Moon definitely affects patients. I worked as an LPN on an Orthopedic Unit (although we had other types of patients too) for 26 years and saw more than my share of crazy happenings when the moon was full. Study or no study I'm a firm believer that a full moon can create havoc!

              • 2 votes
              Reply#8 - Wed Nov 28, 2012 11:06 AM EST

              Most anyone who works in a hospital will tell you that a Full Moon definitely affects patients.

              The article already states that. But with all the studies done to try to see this affect, they have found nothing. Not just this study, but several others.

                #8.1 - Wed Nov 28, 2012 1:40 PM EST

                Maybe because they try to test Mind. They should test effect on Body first. Then, Of course! the body affects our minds.

                  #8.2 - Wed Nov 28, 2012 6:00 PM EST
                  Reply

                  It made me want to shop online. Oh, wait, I do that anyway.

                    Reply#9 - Wed Nov 28, 2012 11:41 AM EST

                    The choice of study patients here must have been done under the influence of a full moon, because it is a little nutsy. Using the category 'people with unexplained chest pains' is not in anyway inclusive of the full range of human behaviors or mood expression!

                      Reply#10 - Wed Nov 28, 2012 12:11 PM EST

                      Money was spent on this??!?!?!

                      • 2 votes
                      Reply#11 - Wed Nov 28, 2012 1:23 PM EST

                      I got a lot of cop friends who would disagree with this study.

                      • 2 votes
                      Reply#12 - Wed Nov 28, 2012 1:27 PM EST

                      They may not show up at the hospitals, but they do show up in public offices.

                      • 1 vote
                      Reply#13 - Wed Nov 28, 2012 1:35 PM EST

                      I have witnessed it myself by the aggression of drivers during the days leading up to and days of Full Moons. I actually pay attention to it. It's not just a myth.

                      Yes, that's the point, exactly. You pay attention to bad drivers during the days leading up to and days of full moons. So, when you see a person driving aggressively on these days, you attribute it to the moon cycle. At other times, you likely don't notice aggressive drivers, or attribute their actions as resulting from from them just being jerks.

                      This is why we need science. The human brain is very good at noticing patterns, even where none exist. There's a great book called How We Know What Isn't So, by Thomas Gilovich, which details the many ways our brains malfunction to find spurious connections to events. This should be required reading in every high school.

                        Reply#14 - Wed Nov 28, 2012 1:36 PM EST

                        I would also add Sagan's The Demon Haunted World to the required reading list!

                          #14.1 - Wed Nov 28, 2012 4:45 PM EST
                          Reply

                          I love how people seem to think that behavior gets stranger and stranger leading up to a full moon, but somehow the day after the full moon things go back to pretty much normal? Um, great, but you know the moon isn't really any different the day after the full moon as it was the day before the full moon? Do these people know that the moon is always the same size? It's just the reflection of sunlight off the moon that changes?

                          I know someone will say that the moon affects tides, and that the full moon has a greater tidal affect than other phases. That's true, and that is because when the moon is in alignment with the sun and earth, the earth feels the combined gravity of those two bodies. But this also happens during a new moon, and so you have the same gravitational effect as a full moon. No one ever sees werewolves or crazier drivers during a new moon...imagine that.

                            Reply#15 - Wed Nov 28, 2012 4:36 PM EST

                            Whoever did this study must have avoided hospitals on a full moon...especially the Psyche floor! Any hospital worker will tell you that the full moon brings out the looney tunes like light attracts moths!

                              Reply#16 - Wed Nov 28, 2012 4:37 PM EST

                              I bet you didn't know that the overwhelming majority of earthquakes around the world occur within 15 days of a full moon? ;-)

                                Reply#17 - Wed Nov 28, 2012 4:54 PM EST

                                Remember how we were told Sandy might hit worse because it came during Full Moon. There is no way to say it doesn't have a Physical affect and the physical affects our behavior. Watch animals who seem to know when a strom is coming. PhysioChenical reactions.

                                  #17.1 - Wed Nov 28, 2012 6:06 PM EST

                                  The info relating to Sandy had to do with tides, not the strength of the storm itself. Stronger tidal influence (which does happen during a full moon, as I explained in my earlier post) would mean a potentially worse storm surge and flooding. It has nothing to do with the strength of the hurricane itself.

                                  Even if you couldn't prove that it doesn't affect our behavior (and make no mistake, it is very difficult to prove a negative so that isn't a stretch), it still doesn't give you free license to make up a cause with no evidence. It's akin to saying "Well I get a headache everytime 'Dances With the Stars' comes on the TV. It's obvious the color spray-tan triggers a response in my brain that causes pain."

                                    #17.2 - Wed Nov 28, 2012 7:30 PM EST
                                    Reply

                                    Sorry, science, I don't believe you on this one. Just because people with mental health issues aren't showing up in the ER on a full moon doesn't mean there isn't plenty of good, old-fashioned weirdness out there when there is one. My coworker and I were just discussing this today - "What the heck is going on?!?" "OMG, it's a full moon!"

                                      Reply#18 - Wed Nov 28, 2012 4:55 PM EST

                                      Check with Police dispatchers - they will tell you there is a difference in people troubles around a full moon.

                                      • 1 vote
                                      Reply#19 - Wed Nov 28, 2012 5:45 PM EST

                                      All I know is, when I moon someone, they go crazy and want to kill me!

                                        Reply#20 - Wed Nov 28, 2012 7:10 PM EST

                                        i don't believe this study for a second. how would they describe the fact that on full moon's i always end up making stupid bets and having to indecently expose myself in public while my friends jeer me on? it doesn't happen at any other point during the lunar cycle... explain that mr. scientist

                                          Reply#21 - Thu Nov 29, 2012 8:44 AM EST

                                          Easy to explain: You are a lunatic.

                                            #21.1 - Thu Nov 29, 2012 9:51 AM EST
                                            Reply
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