Added by Nigel Shelbourne on November 20, 2010
A new study is adding depression to the list of adverse health effects resulting out of exposure to light at night.
Previous research has already suggested that the risk of breast cancer, sleep disorders and even weight gain increases if exposing oneself to light, even dim lights, late into the night.
Now, a recent study adds depression to the list. “We’ve set up a link between exposure to light at night with depression in these animals,” said Tracy Bedrosian at The Ohio State University in Columbus about hamsters involved in the latest study.
The hamsters in a darkness-deprived group were exposed to dim lights similar to the glow of a TV throughout the night, and after eight weeks they reported significantly lower scores on a number of mood tests.
The explanation of the link between light exposure at night and mood is found in melatonin, a hormone that acts as an antioxidant and that regulates our circadian rhythms. It assists us in falling asleep and it controls the release of various other hormones.
It is believed that exposure to light at night causes the body to release the wrong amount of melatonin, or it gets released at the wrong time, causing a number of problems, said Phyllis Zee, director of the Sleep Disorders Program at Northwestern University in Chicago.