Turn in your smartphone before turning in for the night.

President Trump admitted in an interview with Piers Morgan this week that he tweets from bed, often in the early morning or in the evening outside of his daily chief executive duties.

But the POTUS isn’t the only one still glued to his screen when he should be going to sleep. More than half of Americans confess that the last time they check their smartphones for the day is right before going to bed, with 10% saying they will even wake up and check their phones in the middle of the night. And just under half of millennials (44%) actually fall asleep with their phones in their hands.

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But those nightly social media check-ins are wreaking havoc on your sleep, your self-esteem – and your career. Poor sleep costs the U.S. economy $411 billion in lost worker productivity and 1.2 million working days per year. And Americans are spending more than $40 billion on sleep drugs and other sleep aids for a better night’s rest — a number that is expected to hit $52 billion by 2020.

Dr. Natalie D. Dautovich, a National Sleep Foundation environmental scholar and assistant professor of psychology at Virginia Commonwealth University, told Moneyish that we should ideally shelve the screens an hour before getting ready for bed – and to avoid social media in particular. “We have all gone down the rabbit hole of seeing something intriguing or upsetting, so you want to give yourself enough time to digest it, and to relax and unwind,” she said. “We need to be in a calm state in order to transition into sleep, and looking at social media can be both physically and cognitively arousing.”

Here are five reasons to stop using social media as a security blanket before falling asleep.

1. The blue light messes up your body clock. The short-wavelength, artificial blue light that your electronic devices emit has been shown to delay the body’s circadian rhythm (or body clock), so the body doesn’t release the sleep hormone melatonin on cue, and you have a harder time falling and staying asleep.

2. It can make you anxious or depressed. Research has shown that the more adolescents use social media, the greater their risk for depression. And a recent study found that going on social media 30 minutes before bed was the strongest indicator of a poor night’s sleep – partly due to the stimulating blue light, but also because comparing yourself to other people’s posts right before bed could keep you up tossing and turning with envy or FOMO.

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3. You don’t filter yourself as well. Studies have shown that decision fatigue leads us to making poorer and riskier decisions the later it gets in the day, so you could be more likely to share an inflammatory or inappropriate social media post, or write a controversial reply or comment, in the evening versus in the morning or early afternoon. A study of online chess players, for example, found that they started making quicker and riskier decisions that were less accurate in the evening.

4. Just the act of scrolling through social media gives you a jolt. Think about it – going through tweets, Snaps and posts on Instagram and Facebook isn’t a leisurely, relaxing process. You’re scrolling or swiping through dozens of posts a minute. “We are shifting quickly through content, and that in itself requires different attentional processes which can be activating,” said Dr. Dautovich. “The constant switching is in itself stimulating.”

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5. It’s linked with less quality sleep. We cycle through lighter and deeper sleep phases during the night, ideally without waking up as we transition in and out. “But if we have seen something stimulating before bed, whether it’s media content, or something we read that we’re still digesting, we’re at a greater risk of awakening during those transition periods,” explained Dr. Dautovich, which makes that night’s sleep less restorative. Research has found that college-age adults who check social media sites during typical sleeping hours are more likely to suffer daytime tiredness and cognitive impairment, for example.

Dr. Dautovich also suggested some tips to weaning yourself off of your screens at night.

Charge your phone or tablet in another room. “Even the sight of your phone can be arousing or stimulating,” warned Dr. Dautovich. It compels you to pick it up and check your notifications. So try charging your phone overnight in another room, so that you’re not even tempted to look at it. Or at least set it across the room on a dresser or shelf that’s away from your bed.

Read an actual book instead of an ebook. While there are some e-readers like the Kindle Paperwhite (versus the Kindle Fire) that don’t produce the same sleep-wrecking blue light, Dr. Dautovich recommends reading a printed book under lamplight, or even listening to an audio book until you get sleepy. Research finds that reading for just six minutes before bed has been shown to reduce your stress levels by two-thirds, better helping you to drift off.

Write out a to-do list. A recent study found that making a to-do list for the next day can help you fall asleep 10 minutes faster. “It can help to compartmentalize the day from the night,” explained Dr. Dautovich, “and to recognize that nighttime is reserved for sleeping, and taking a break from all of those activities.” And writing out what you need to do tomorrow gets those worries out of your mind, and onto the page.

Keep the room dark and cool. “The more cave-like, the better,” said Dr. Dautovich, who recommends switching off all light sources and getting blackout curtains for your windows. Minimize noise, or mask it with a sound machine playing soothing music or ambient, white noises like softly falling rain or crashing waves. And lower the temperature. “We know [from research] that a cool bedroom — cool meaning between 50 and 68 degrees Fahrenheit – helps the transition into sleep,” she added.