Study shows light present at nighttime can cause depression

Researchers from Ohio State University found that exposure to dim light at night causes depressive symptoms.

The study showed that alterations occur in the hippocampus part of the brain, which controls long-term memory and spatial navigation, in Siberian hamsters that were exposed to dim light every night for eight weeks.

Researchers examined the hippocampus and found significantly reduced density of dendritric spines – hair-like growths on brain cells that help send chemical messages from one cell to the other.

They believe that lower levels of melatonin caused by the light at night results in this condition.

Researchers said that the light used in the study was equivalent to having a television on in a darkened room. To test for depressive symptoms, officials measured how much sugar water the hamsters drank. The study found that the hamsters exposed to dim light drank less sugar water than those in the control group.

According to the National Institute of Mental Health, nearly 15 million people in the U.S. suffer from major depressive disorder.