Moonlight and Sleep: What Science Says

The full moon has long been blamed for keeping people awake and causing strange behavior. The word "lunacy" even comes from the Latin word for moon. But does the moon really affect our sleep and mental health?

Sleep and the Full Moon

Research shows that the full moon can have a small impact on sleep. People tend to sleep about 20 minutes less and take longer to fall asleep during the nights leading up to a full moon. This is likely because the bright moonlight can delay the body's internal clock and reduce melatonin, the hormone that helps us feel sleepy. The effect is stronger in places without artificial light, like rural areas or while camping.

Mental Health and the Full Moon

The idea that the full moon causes mental health problems is less clear. While sleep loss can worsen mental health, there is no strong evidence that the moon directly causes psychiatric crises. Some studies have found small effects, but these are not consistent worldwide and may be influenced by cultural factors or local hospital practices.

Other Theories

Scientists have explored other explanations for the supposed lunar effects, such as gravitational pulls or geomagnetic changes. However, these theories do not hold up under scrutiny. The most plausible link between the moon and human behavior is the disruption of sleep caused by nighttime light exposure.

Why Do We Believe in the Full Moon Effect?

Psychologists suggest that we notice and remember the unusual nights that coincide with a full moon but forget the many nights when nothing happens. The moon is also highly visible, making it an easy target to blame for our sleeplessness.

The Importance of Light at Night

Even if the moon does not drive us "mad," its small influence on sleep highlights the importance of light at night. Our bodies are designed to follow the natural cycle of light and dark, and extra light in the evening can lead to lighter, more fragmented sleep. This same biology helps explain the health risks of daylight saving time, which can disrupt our circadian rhythms and contribute to increased accidents and cardiovascular risks.

Modern Light and Sleep

In our modern world, artificial light has a much bigger impact on sleep than the moon ever will. So if you find yourself restless on a full moon night, it might not be the moon's fault. It could be the light from your phone or computer screen keeping you awake.