Sleeping in a room with even dim artificial light, such as the glow of the television or a night light, can cause depression, a study published July 24 suggests. But the good news: you can reverse the effects by simply switching off the lights.
The new research adds to a growing body of evidence that finds that light at night can cause changes to the brain and depressive symptoms. Plus the researchers believe that staying up late to watch television or go online could also play a factor in depression.
In the study, hamsters exposed to dim light at night for four weeks showed signs of depression, such as less interest in drinking sugared water that they previously enjoyed, compared with the control group, the researchers said.
The findings suggest exposure to artificial light at night could be contributing to the rising rates of depression over the last 50 years, according to study researcher Tracy Bedrosian, a doctoral student in neuroscience at Ohio State University in the US.
"The advent of electrical lighting permitted humans to stray from natural day-night cycles," which could potentially disrupt our biological rhythms, Bedrosian said.
Undo the effects
"People who stay up late, in front of the television and computer, may be able to undo some of the harmful effects just by going back to a regular light-dark cycle and minimizing their exposure to artificial light at night," Bedrosian said.
Prior research has found exposure to artificial light at night may increase the risk of weight gain and some kinds of cancer.
The study was published online in the journal Molecular Psychiatry.