Night light can cause depression


New research shows that people who stay up late working or playing on computers have a higher chance of developing depression and learning problems not just because of a lack of sleep, but also because exposure to bright light during the dark hours of the night can increase cortisol levels.

The light from a computer monitor, a laptop or even an iPad is enough to bring on the condition.

Alters mood and ability to recall information

“Basically, what we found is that chronic exposure to bright light – even the kind of light you experience in your own living room at home or in the workplace at night if you are a shift worker – elevates levels of a certain stress hormone (cortisol) in the body, which results in depression and lowers cognitive function,” explained Samer Hattar, a biology professor in the Johns Hopkins University Krieger School of Arts and Sciences.

Lack of interest and depression-like behavior

The study followed the behavior of mice. “Of course, you can’t ask mice how they feel, but we did see an increase in depression-like behaviors, including a lack of interest in sugar or pleasure seeking, and the study mice moved around far less during some of the tests we did. They also clearly did not learn as quickly or remember tasks as well.”

At night, use only the light you need

People need to know that exposure to bright light during what is typically a night-time sleep cycle can impact their mood and ability to learn. “I’m not saying we have to sit in complete darkness at night, but I do recommend that we should switch on fewer lamps, and stick to less-intense light bulbs: Basically, only use what you need to see,” Hattar concluded.

Sources: Nature, MedicalNewsToday

Photo by John Nyboer


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