Switching off your TV or computer before bed may help to prevent depression, new research suggests.
A study on animals by researchers at the Ohio State University Medical Centre found that exposure to dim lighting at night from electronic displays and other sources may lead to mood disorders.
Siberian hamsters were exposed to different light and dark conditions for four weeks. Half of the animals received a chronic dim light setting - the equivalent to having a TV on in a dark room - throughout the night.
When compared with the hamsters exposed to complete darkness, those that experienced low light lacked energy, motivation and were less likely to drink their sugar water.
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“The results we found in hamsters are consistent with what we know about depression in humans,” said Tracy Bedrosian, one of the authors of the study.
The findings highlighted changes in the tissue of the hippocampus which were similar to changes found in people with depression.
Within a week of returning to a standard light-dark cycle, the hamsters had made a full recovery.
Researchers say that the rise in exposure to artificial light at night over the last 50 years has coincided with rising rates of depression, especially among women.
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Light pollution can come from electronic displays, overhead lighting in the home as well as streetlights, passing traffic and neighboring buildings.
“The good news is that 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 minimising their exposure to artificial light at night,” Bedrosian says. “That’s what the results we found in hamsters would suggest.”
The results are published in the Molecular Psychiatry journal.