A new study from the Indiana University School of Medicine has found that deaths by suicide significantly increase during the week of a full moon. The research, which was published in the journal Discover Mental Health, analyzed data from the Marion County coroner’s office in Indiana about suicides that took place from 2012-2016.
Study lead author Dr. Alexander Niculescu explained the rationale behind the research: “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.”
The researchers found that people over the age of 55 showed an even higher increase in suicides during the week of a full moon. In addition, the experts looked at the time of day and month when suicides occurred and found that 3 to 4 p.m. and the month of September were peak times.
“From a clinical perspective and a public health perspective, we found some important take-home messages in this study,” said Dr. Niculescu. “High-risk patients should possibly be followed more closely the week of the full moon, during late afternoons and perhaps the month of September.”
The team of researchers also previously developed blood biomarker tests for other mental health conditions such as anxiety, depression, and post-traumatic stress disorder, as well as for pain. In this study, they were able to use blood samples previously taken by the coroner from some of the people who died by suicide to determine which biomarkers were present.
“We tested a list of top blood biomarkers for suicidality that we identified in previous studies,” said Dr. Niculescu. “The biomarkers for suicidality that are predictive of death by suicide during full moon, peak hour of day and peak month of the year compared to outside of those periods appear to be genes that regulate the body’s own internal clock, so called ‘circadian clock’. Using the biomarkers, we also found people with alcohol-use disorder or depression may be at higher risk during these time periods.”
According to Dr. Niculescu, the surge in suicides during the full moon phase could be attributed to the heightened luminosity. The body’s circadian rhythm, which regulates our sleep-wake cycle over 24 hours, is significantly influenced by the surrounding light. Moonlight could be disrupting people’s natural rhythms during the period when it should be dimmer.
“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.”
Dr. Niculescu mentioned that there are two additional peak periods for suicides. The first peak occurs from 3 to 4 p.m. and may be connected to the accumulation of stressors throughout the day, as well as a reduction in daylight which leads to lower expression of circadian clock genes and cortisol. The second peak happens in September, which coincides with the end of summer vacations and the onset of seasonal affective disorder symptoms as the amount of daylight decreases during this time of year.
“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.”
In the future, Dr. Niculescu hopes to study if exposure to screens at night contributes to increased suicidality in people, especially younger people. “Some people have a full moon in their hand every night. It’s an area we absolutely need to study further.”
While the idea that a full moon can cause strange behavior has been around for centuries, there is little scientific evidence to support the claim. However, this study provides some evidence that there may be a correlation between the full moon and an increased risk of suicide, particularly among older adults.
It’s important to note that correlation does not necessarily equal causation, and the study has limitations, such as being limited to data from one county in Indiana. Further research will be needed to determine if these findings can be replicated in other locations and populations.
Nonetheless, the findings provide important insights into the patterns of suicide, and could help inform suicide prevention efforts. As Niculescu noted, “These findings underscore the importance of more research into the factors contributing to suicide risk, and suggest that paying closer attention to the timing of suicides could help save lives.”
Full moons and human behavior
There is ongoing debate and controversy regarding the extent to which the full moon can impact human behavior. While some studies have suggested that the full moon may have a subtle influence on human physiology and behavior, other studies have failed to find any significant effects.
One of the most commonly discussed effects of the full moon is its potential to influence sleep patterns. Some researchers have found that people tend to sleep less deeply and experience more interrupted sleep around the time of the full moon.
This may be due to the moon’s gravitational pull, which can affect the tides and may also affect the fluids in our bodies. However, other studies have failed to replicate these findings, so the evidence for this effect is mixed at best.
Another potential impact of the full moon on human behavior is its association with changes in mood and mental health. Some people report feeling more anxious or agitated around the time of the full moon, while others may experience a boost in energy and creativity.
However, again, the evidence for these effects is inconclusive and may be influenced by a range of other factors, such as cultural beliefs and expectations.
It is also worth noting that many of the studies on the effects of the full moon have been criticized for being poorly designed or for relying on anecdotal evidence rather than rigorous scientific methods. To fully understand the potential impact of the full moon on human behavior, more research is needed using rigorous experimental designs and objective measures of behavior and physiology.
In summary, while there is some evidence to suggest that the full moon may have a subtle influence on human behavior, the scientific evidence for this effect is far from conclusive. As with many other areas of scientific inquiry, more research is needed to fully understand the potential impact of the full moon on human physiology and behavior.
