Getting a good night’s sleep, it seems, is going the way of AM radio and dial-up internet. But are screens really to blame? We examine the evidence.

It's not just you. Screen-time across the developed world, in every age range, has gone through the roof.

Among the youngest age groups, it's increased fivefold over the past 20 years. And that was before the pandemic hit.

Teens increasingly report being online “almost always.” And average adult device usage has soared by up to 500% in the past year.

So … that’s a lot.

Asleep at the wheel?

At the same time, the quantity and quality of sleep we’re getting has plummeted. 

The problem had become so dire - and again, this was in the Before Times, pre-COVID - that in April last year, parliament ordered a federal inquiry to understand our increasingly poor sleeping habits. 

Close to 60% Australian adults show at least one sleep disorder symptom, of which 14.8% have definite symptoms of insomnia. Few seek help.

25% of 12 to 15-year-olds in Australia don’t sleep for the prescribed 8 to 10 hours on school nights. Among 16 to 17-year-olds, the figure is 50%.

A longitudinal study of sleeping patterns of school-aged children in Australia found a reduction in sleep duration of approximately 30 mins across a 20-year period.

As few as 20% of us sleep through the night uninterrupted, while among teens,  77% experience sleep problems, including night waking and difficulty falling asleep. 

And often these problems become severe enough for a clinical diagnosis of insomnia.

In the UK, hospitalizations for insomnia in those aged 16 and under doubled between 2012 and 2019, while prescriptions for the sleep-inducing hormone melatonin increased by 25%.

A wake-up call

Figures like this have been a wake-up call for policymakers - because lack of sleep has serious, and costly, implications for health and wellbeing. Consider that 

• 40% of sleep-deprived Australians die of heart disease and diabetes.
• 20% of us have fallen asleep while driving 
• 80% report being less productive after sleeping poorly.

Why screen-time is a sleep vampire

The data is clear that there is a strong negative correlation between screen-time and sleep - which is a fancy way of saying that as time on devices increases, sleep decreases.

But correlation is not the same as cause-and-effect. For example, the rate of my hair growth may be correlated with rises in the consumer price index - but one does not cause the other.

In the case of screen-time and sleeplessness, however, the science shows a causal link too strong to ignore - especially with regard to using screens at bedtime.

While people have been falling asleep in front of the television for generations, today’s screen-use patterns are different. For one thing, our devices are so portable, it’s an easy matter to bring them right into bed with us.

What’s more, the content we typically interact with today is far more interactive and stimulating - playing video games, for example, or using social media. And it’s exactly those  qualities that are  literally keeping us up at night. 

An extensive and growing body of scientific research shows 

• Screen use in the final hour before sleep is associated with shorter overall sleep duration and more difficulty in falling alseep.
• Night-waking due to interruptions from devices (social media messaging, notifications, text messages, etc.) is increasingly common, and is associated with daytime exhaustion.
• The risk of insomnia increases if multiple screens are present in the bedroom.

3 ways screens affect sleep

But why does this happen? Studies show there are three main ways screen-time affects sleep:

By delaying sleep onset, which in turn results in fewer hours of sleep.

By increasing psychological and cognitive arousal, and again this is particularly true for content such as violent or highly stimulating video games. 

By increasing exposure to blue light. Although exposure to any type of light suppresses the production of the sleep hormone melatonin, numerous studies have shown that the specific light (short-wavelength blue light) emitted from the screens of digital devices is particularly disruptive.

The take-home message?

The message is loud and clear: For longer and sounder sleep for the whole family, keep devices out of bedrooms. 

Switch off all devices (including your own, Mum and Dad ...) at least 30 minutes before lights out - longer if content is especially stimulating. 

Charge devices outside of the bedroom, and buy some old-school alarm clocks. If that seems too extreme, consider setting devices to “Do Not Disturb” to limit or block notifications.