One in 12 video game players have an unhealthy "addiction" to the pastime, an Australian study shows.
Researchers at the University of Sydney conducted an online poll of almost 2,000 gamers from across the globe.
They were quizzed on their duration of play and how they measured up against a checklist of negative side-effects including reduced school or work performance, interrupted sleep patterns, cravings when not playing, related weight loss or gain, sore eyes or carpel tunnel syndrome.
Associate Professor Vladan Starcevic said a "minority" of 8% were found to fit the study's problem gamer profile.
"Their whole lives revolve around this activity and there certainly seems to be a problem there - there is an addiction," Starcevic said.
"And it seems to us that these people seem to ... have other mental health issues, and it seems excessive video game playing is a manifestation of these underlying problems."
The problem gamers were found to be more likely to be socially isolated, have a higher risk of depression and be more prone to compulsive behaviour.
Starcevic said just over 70% of the problem gamers were playing for more than four hours daily.
They also reported cases of playing for longer than they planned, and at times when they "did not want to and despite knowing they should not".
Starcevic said these people also tended to prefer playing open-ended and community-based online computer games such as World of Warcraft.
Alternatively, Starcevic pointed to the 92% of gamers who he said had a healthy enjoyment of video games.
"It's quite safe to conclude that," he said.
"Most people who play video games are not problem video game players, to put it in simple terms, they're not addicted to video games.
"It is a minority of people who seem to have a problem."
Thirty per cent of these gamers still reported playing more than four hours daily.
Almost half of the study respondents were based in the USA or Canada, 25% were from Europe and about 20% were from Australia/New Zealand.
Starcevic presented the research results at the Royal Australian and New Zealand College of Psychiatrists Congress, which is underway in Adelaide this week.