In a recent study released in the online journal BMJ Open, too much "screen time" was associated with increased levels of anxiety in children. The research was used to back the Public Health England (PHE) campaign, which includes tips for parents on ways to reduce sedentary time, increase exercise, and improve diet. Among other things, the report associated excessive "screen time" with anxiety, depression, low levels of self-esteem, and emotional problems.
According to Professor Kevin Fenton, director of health and wellbeing at PHE, “The greater the time spent in front of the screen, the greater the negative impact on both behavioural and emotional issues relating to the child’s development.” While the study linked a general increase in sedentary activity to to a decrease in physical activity, there were also specific findings that linked time on computers and video games to emotional distress and depression.
It's not only children who are at risk from too much "screen time", however, with other studies linking hand-held digital devices with sleep disorders and emotional problems. In a recent study by Australian researcher Professor Shantha Rajaratnam from Monash University's School of Psychology and Psychiatry, the growth in tablet and smartphone use at night was found to have a negative effect on melatonin production and sleep patterns.
"We think that the advent of electric lighting has significantly impacted upon sleep-wake patterns, but with the proliferation of electronic devices that emit light we are expecting that these problems will increase," said Professor Rajatnam. The average level of light emitted by digital devices is between 30 to 50 lux, which is roughly half the illumination of an ordinary room light. However, the blue light from screens has been found to have a particular effect on our brains, making it difficult for us to turn off when we hit the pillow.
The short wavelength blue light produced by digital screens is much more disruptive to our body clock than regular lighting, suppressing melatonin and delayingnatural sleep patterns. According to Clinical psychologist Dr Amanda Gamble, from Sydney's Woolcock Insomnia Clinic via the ABC, people are "at much greater risk of later developing anxiety disorders, depressive illnesses, substance abuse issues and also, on the more physical side, they're at increased risk of poor glycaemic control, diabetes and so on."
Many of the problems associated with too much "screen time" can be moderated by balancing sedentary time with physical exercise and placing limits on how oftenchildren use digital technology. In terms of sleep patterns, according to Professor Rajaratnam, the best solution is also the simplest: "We would recommend that these devices are shut down or closed off up to two hours before bed time, but at least one hour before bed time, to try to reduce the impact of these light sources on sleep."