Why buying blackout shades could be an investment in your mental health

There are countless pesky ways your sleep can get disrupted. Maybe the baby down the hall has seemingly been crying for three years, or your upstairs neighbor is making so much noise that you wonder if he’s opened a CrossFit gym annex in living room. Perhaps you’re simply too hot. Or your otherwise lovely significant other snores. It’s all so irritating. But one snooze interruptor might stand above the rest in regard to long-lasting, harmful effects.

According to a new study published in the American Journal of Epidemiology, even a little bit of light in your room at night can lead to depressive symptoms. So if you’ve been hemming and hawing over splurging on a solid set of blackout shades, science has your back on this very worthy investment.

People who saw more light at night were more likely to develop symptoms of depression than those who slept in total darkness, according to the study.

From 2010 to 2014, researchers added light to the bedrooms of 863 elderly Japanese adults (average age 71.5) who did not have depressive symptoms, then compared those results to a control group of people who slept in a dark room. Exactly 73 adults in the bedrooms with light developed depressive symptoms during the study’s follow-up period—a much higher rate than that of the control group. These results led researchers to conclude that people who saw more light at night were more likely to develop symptoms of depression than those who slept in total darkness.

“Maintaining darkness in the bedroom at night may be a novel and viable option to prevent depression.” —Dr. Kenji Obayashi, study co-author

“Maintaining darkness in the bedroom at night may be a novel and viable option to prevent depression,” study co-author Kenji Obayashi, MD, PhD, a community health and epidemiology professor at Nara Medical University School of Medicine in Japan, told Time.

Though the study authors don’t know exactly how light is connected to depression, they acknowledge that it’s a sleep disturbance that may throw off the body’s internal clock, Time reported. (Not to mention that sleep and depression are very likely to be related.) And though this study focused on elderly adults, Dr. Obayashi told Time that the results could be even more significant among younger people with sharper, more sensitive eyes.

So after you draw those blackout shades, consider shutting down your phone, turning off your TV, and closing your laptop. Sorry, nighttime Netflix addiction, but mental health trumps bedtime bingeing.

Here’s exactly what you need to do to upgrade your bedroom for quality shut-eye. And while you’re adding blackout curtains to your cart, consider a weighted blanket, too.