The amount of time children spend in front of screens should be curbed to stave off development and health problems, an expert says.
Psychologist Dr Aric Sigman says children of all ages are watching more screen media than ever, and starting earlier.
The average 10-year-old has access to five different screens at home, he says.
And some are becoming addicted to them or depressed as a result, he warns.
Writing in the Archives of Disease in Childhood, Dr Sigman says a child born today will have spent a full year glued to screens by the time they reach the age of seven.
He adds: “In addition to the main family television, for example, many very young children have their own bedroom TV along with portable hand-held computer game consoles (eg, Nintendo, Playstation, Xbox), smartphone with games, internet and video, a family computer and a laptop and/or a tablet computer (eg iPad).
“Children routinely engage in two or more forms of screen viewing at the same time, such as TV and laptop.”
Dr Sigman cites from a string of published studies suggesting links between prolonged screen time and conditions such as heart disease, stroke and diabetes.
But he suggests the effects go further than those simply associated with being sedentary for long periods.
He says prolonged screen time can lead to reductions in attention span because of its effects on the brain chemical dopamine.
Dopamine is produced in response to “screen novelty”, says Dr Sigman.
It is a key component of the brain’s reward system and implicated in addictive behaviour and the inability to pay attention.
“Screen ‘addiction’ is increasingly being used by physicians to describe the growing number of children engaging in screen activities in a dependent manner,” Dr Sigman says.