IU study shows death by suicide increases significantly during week of full moon

INDIANAPOLIS — For centuries, people have suspected a full moon causes mysterious changes in people’s behavior.

Psychiatrists at Indiana University School of Medicine studied data from the Marion County Coroner’s Office and found deaths by suicide increase during a full moon.

“We wanted to analyze the hypothesis that suicides are increased during the period around full moons and determine if high-risk patients should be followed more closely during those times,” Alexander Niculescu, Professor of Psychiatry at IU and leader of the study, said.

The team found that deaths by suicide, recorded by the coroner’s office, increased significantly during the weeks of a full moon from 2012-2016. People 55 and older showed an even higher increase during this time.

The team also found that suicide attempts are more likely to happen between 3 to 4 p.m. and the month of September tends to be the peak month for deaths by suicide.

Niculescu said our circadian rhythm is the reasoning for this, which is the natural 24-hour cycle our bodies follow to regulate when we are asleep and are awake.

The team claims light from the moon could be impacting people when it should be darker, leading to an increase in suicidal thoughts.

“The effect of ambient light and body clocks in suicide needs to be studied more closely, along with how people sleep and their exposure to light,” Niculescu said. “Changes in light can affect vulnerable people, in conjunction with other risk factors.”

According to Niculescu, the peak time for suicides being 3 to 4 p.m. could be related to stressors during the day, as well as a decrease in sunlight beginning at that time of the day.

As far as the peak month for suicides being September, Niculescu says many people are experiencing the end of summer vacations as well as seasonal disorder effects beginning to kick in during the fall season.

“Our work shows the full moon, fall season and late afternoon are temporal windows of increased risk for suicide, particularly in individuals who suffer from depression or alcohol use disorders,” Niculescu said. “Some people have a full moon in their hand every night. It’s an area we absolutely need to study further.”