We’re addicted to screens. Survey data conducted in America suggests the population collectively check their phones 8 billion times, every day.
And all that screen time has meant less bedtime.
According to a new study published in the journal PLOS ONE, people who used their phones a lot, particularly around bedtime, got less – and worse – sleep than their peers.
“There’s growing evidence that poor sleep quality is not simply associated with difficulty concentrating and being in a bad mood the next day,” says Dr. Gregory Marcus, one of the study’s authors and director of clinical research for the division of cardiology at University of California, San Francisco.
“[Poor sleep] may be a really important risk factor to multiple diseases.”
In the month-long study, 653 adults downloaded a background app that tracked the user’s screen time. The participants recorded how long, and how well, they slept following normal sleep scales.
The researchers found people interacted with their phones roughly 3.7 minutes per hour, with times surpassing that seeming to come at a detriment.
“We found that overall, those who had more smartphone use tended to have reduced quality sleep,” Marcus says.
Having said that, the study doesn’t prove that using screens will equate to a bad night’s sleep. It could actually be the other way around: “We can’t exclude the possibility that people who just can’t get to sleep for some unrelated reason happen to fill that time by using their smartphone,” Marcus says.
But, there have been other studies that support the hypothesis that screens ruin your slumber. For example, this data suggests the blue light your phone emits suppresses melatonin, a hormone responsible for maintaining healthy circadian rhythms.
“We also know that emotional upset, or just being stimulated apart from smartphone use, can adversely affect sleep quality, and that engaging with Twitter or Facebook or email can cause that sort of stimulation,” Marcus says.
That being said, screen time and its effects will vary from person to person.
But if you’re one of those people that simply can’t find a good night’s sleep, look to your smartphone (or rather, away from it).
“Because sleep quality is so important, I think it’s useful for individuals to take these data and at least give avoidance of their smartphones an hour or so before they go to bed a try to see if it helps.”