It’s a habit many of us have, cuddling up in the bed at night with our little companion, the laptop.
Many a gripping series or Facebook mail has been watched or written by us as we plop back against the pillows.
But now research has shown that using your laptop or tablet in the evenings could put you at risk of depression.
Researchers have found exposure to bright light at night elevates levels of a stress hormone in the body which triggers the condition and reduces the ability to learn.
“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 in the body, which results in depression and lowers cognitive function,” Study leader Samer Hattar, from Johns Hopkins University in the U.S, told the Daily Mail.
In the history of humanity, humans lived by the sun and slept when darkness came. However, now people are working, living or partying into the early hours of the morning.
The new study on mice revealed how these habits could have a detrimental effect on our health.
It demonstrates how special cells in the eye are activated by bright light, affecting the brain’s centre for mood, memory and learning.
Put away the laptop!
Professor Hattar said: “Mice and humans are actually very much alike in many ways, and one is that they have these cells in their eyes, which affect them the same way.
“In addition, in this study, we make reference to previous studies on humans, which show that light does, indeed, impact the human brain’s limbic system. And the same pathways are in place in mice.”
The scientists are aware that shorter days in the winter cause some people to develop a form of depression known as ‘seasonal affective disorder’, or SAD, and that some patients with the mood disorder benefit from ‘light therapy’ which is simple, regular exposure to bright light.
Hattar believed the mice would react the same way.
“Of course, you can’t ask mice how they feel, but we did see an increase in depression-like behaviours, 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. They were not as interested in novel objects as were mice on a regular light-darkness cycle schedule.”
He said the animals also had increased levels of cortisol, a stress hormone that has been linked in numerous previous studies with learning issues.
The results, published in the journal Nature, indicate that humans should be wary of the kind of prolonged, regular exposure to bright light at night that is routine in our lives, because it may be having a negative effect on our mood and ability to learn.
“I’m not saying we have to sit in complete darkness at night,” Mr Hattar said, “But I do recommend that we should switch on fewer lamps, and stick to less-intense light bulb.”
We might have to give Homeland a skip in the bedroom tonight…
