PRESCHOOLERS are developing violent behaviour after being allowed to play M-rated video games.

The shocking revelation comes as psychologists report a rise in calls about children who are addicted to computer games and the internet.

The condition known as "pathological internet misuse" is growing so rapidly among Australian children that it could soon be formally recognised as a mental health disorder.

The Herald Sun has learnt that international mental health experts are considering including "video game addiction and internet addiction" in the next edition of the globally recognised Diagnostic and Statistical Manual of Mental Disorders (DSM-5) "to encourage further study".

Child psychologist Emma Butler says teenagers are not the only ones who are spending dangerous amounts of time in front of the video games.

"Teenagers don't usually become violent from playing violent games - it's the under-fives that emulate the behaviours they see on TV or in video games," she said.

"I have seen under-fives who have been playing M-rated games. The parents don't seem to take the ratings as seriously as they do for television or other media."

Psychology Melbourne's David Conti, who specialises in addiction treatment, said video and internet abuse was becoming a "common complaint" because of its availability.

"It's very hard to control it or limit it because they can always log on using wi-fi on their way to school," he said.

"It's hard to say what the full ramifications will be because the technology is still so new."

Mr Conti said children who abused the internet often withdrew socially, failed to exercise properly and neglected their school work.

Some acted out fantasies of revenge and power through their games.

One mother said her 13-year-old son was so addicted to computer games he had attended school only intermittently during the past two years and violently resisted attempts to remove him from in front of the screen.

Leading researchers this week will launch the first online mental health education program aimed at weaning youngsters off their addiction.

Originally published as Video games turning kids violent