Neighbours are shocked by an eight-year-old boy who shot and killed his grandmother minutes after playing Grand Theft Auto IV, US authorities said. Sky News.

VIDEO game-addicted kids are playing nonstop for days on end, dropping out of school and developing mental illnesses, top experts say.

Addicts include children as young as eight and some parents are finding themselves being laughed at by GPs when they try to seek help.

Some of Australia's leading experts will speak out about the epidemic at a conference on Friday and say the impact of technology on the minds of young children needs to be taken more seriously by health professionals.

Dr Philip Tam, a child and adolescent psychiatrist at Sydney University, said there were "probably hundreds or thousands" of children aged between eight and 14 with "significant problems" related to their video game and internet use.

The most severe cases have resulted in children dropping their grades or out of school completely while others are becoming violent towards their parents and developing mental illnesses.

"I'm actually getting calls from all over Australia," Dr Tam said.

"I've been getting probably 50 to 100 calls from all over Australia from parents willing to bring (their children) literally from Tasmania or the Gold Coast to come and see me (in Sydney) because they are so desperate."

Dr Tam, who will speak on the topic at the Australian Council on Children and the Media conference, said he had treated one child who played video games for "about 60 hours nonstop, with no sleep".

Up to 10 per cent of children fall into the category of overusing video games and a small number of those children develop addictions, Dr Tam said.

"I've had kids that don't realise when they get into the zone that it's five o'clock (in the morning) when they finish gaming," he said.

"They play all night and by sunrise or by 11 or 12 they're so exhausted they go to sleep (and do not go to school).

"I'm seeing a child right at the moment who we're struggling with who is in that situation."

Dr Tam said some child psychologists in Sydney dealt purely with gaming addiction but the overuse of video games needed to be taken more seriously by the broader health profession.

He said he had spoken with parents who said they were laughed at by their general practitioner when they sought help for their child being addicted to gaming.

Dr Kate Highfield, a lecturer at the Institute of Early Childhood at Macquarie University, said parents were confused about what apps to download for their children to use on iPads and other devices.

She said the majority of the most popular apps that claimed to be educational were questionable in how much they helped children and parents needed to vet the ways their children were using technology.

Most children aged under eight already exceeded the recommended three-hour daily limit using media but that time could be productive if it was used in the right way, she said.

"(Parents) need to be present in the digital playground ... participating with (their children)."

Dr Wayne Warburton, the deputy director of the Children and Families Research Centre at Macquarie University, said issues for young people were amplified by the amount of exposure they had to violent video games.

Studies have shown people to become more aggressive, fearful, hostile and emotionally desensitised to some images.

He said even people who were exposed to violent media over a period of 30 minutes showed less of an emotional response to what they were watching than when they started.

"In other studies that look at people who have had a lot of exposure to violent media ... you tend to find those people don't have the same sorts of emotional responses to violence (and) might have a decrease in empathy," he said.

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