Night lights can cause mood swings

By Casey Frye, CCNN Writer

I know loads of people who use night lights around their house. Some people use them to fend off those scary monsters under the bed. Others use it to light the dark hallways to avoid painfully stubbing their toes on any objects. If you have a favorite color, there is no limit to colors a night light can be. If you have too many to choose from, you may like the one that alternates between red, white, green, and blue lights. It looks so cool! That may be, but according to Ohio State University, it may be a source of mood swings.

You see, the back of our inner eyeball – called the retina – has cells that are sensitive to certain colors of light. When they detect any, the cells send a signal to the part of the brain responsible for making us feel sleepy or lively.

“These cells are most sensitive to blue [light] and least sensitive to red [light],” said Randy Nelson, a professor at Ohio State University. “We wanted to see how exposure to these different [colors] affected the hamsters.”

The professor and his team took some hamsters and studied them for 4 weeks. They had the tiny furballs sleep in a room that was lit with either blue, red, green, white, or no light. Apparently, the different colors affected how the rodents felt. For example, the hamsters in the blue and white light were really sad (awww, poor them, I wish I could give them a hug to make them cheer up). On the other hand, the hamsters that spent their nights in red light were not sad at all. In fact, they were kind of happy. The jolliest of the bunch, though, were the ones that slept in complete darkness! Tracy Bedrosian, a researcher who worked in the study, had an explanation for all of this.

“Light at night may result in parts of the brain regulating mood receiving signals during times of the day when they shouldn’t,” said Bedrosian. “This may be why light at night seems to be linked to depression.”

The team mentioned this research can be applied to humans, too! So, if you are someone who uses a night light, it may be better for you not to use one. If you absolutely need to, though, try using a red bulb!

Featured image courtesy of Ray Bouknight on Flickr.