Parents have suspected it for years, but now they have medical proof: the more time spent on a computer or mobile phone, the less sleep a teen will get - especially if used just before bedtime.
A study by Bergen centre for child health has been conducted with nearly 10,000 people aged 16 to 19, which asked teens about their sleeping patterns, how long they looked at a screen outside of school hours and the type of gadgets they used.
Those who took part in the research said they needed between eight and nine hours sleep on average to feel rested. Those with screen time of more than four hours per day were three-and-a-half times more likely to sleep fewer than five hours at night and were 49 percent more likely to need more than 60 minutes to fall asleep.
It was discovered that using an electronic device, even an hour before bedtime, badly affects both the onset of sleep and sleep duration. In particular, teens who used a computer or mobile phone in the last hour were 53 percent more likely to lose out on two or more hours of sleep.
The main detrimental effects that the use of technology had on sleep that the research found was that the bright light and media content from devices such as tablets, smartphones and televisions, interferes with the signals in our brain which tell us when we need to sleep this means we prolong the time we feel the need to stay awake.
The evidence is so strong that experts said, health watchdogs should overhaul guidelines for electronic device use by youngsters. "The recommendations for healthy media use given to parents and adolescents need updating, and age specific guidelines regarding the quantity and timing of electronic media use should be developed," said Mari Hysing, the study leader.
Our resident sleep expert Dr Nerina comments, "Winding down properly before getting in to bed is crucial to helping you sleep better. You are more likely to access efficient deep sleep if you allow your body and mind to relax. Avoid checking your emails or social media accounts 90 minutes before going to bed - put your phone, laptop and tablet away! Your bedroom is your personal sanctuary and should be a technology free zone."
For more sleep tips and information visit Dr Nerina's Sleep Toolkit.