Children's aggressive, rude and uncooperative behavior linked to their addiction to computer games by researchers in a new study.
Even during term-time they are spending 16 hours or more a week playing games outside school hours.
And one 15-year-old boy admitted spending 18 hours a day playing computer games during his school holidays.
The British Association of Anger Management warned on Monday that the youngsters start to withdraw from family life and interaction with friends but many parents ignore the problem in order to avoid confrontations.
It surveyed 204 parents of children aged nine to 18 about their use of computer games.
46 percent said their sons or daughters had become 'less co-operative' since they started playing video games.
44 percent said that they were more 'rude or intolerant towards others', 40 percent said that they were more impatient, 36 percent reported an increase in 'aggressive behaviour', 29 percent cited more mood swings and 26 percent said their offspring had become more reclusive.
28 percent admitted their children spent 16 hours or more a week playing computer games.
"We get a fair amount of young people that are referred to us by their parents, whereby they are playing up in their school and home life," the Daily Mail quoted Mike Fisher, director of the association, which provides one-to-one sessions for children, as saying.
"There's a very high percentage that we work with who are compulsive, obsessive online gaming addicts," he said.
Children being treated through anger management programmes range in age from 13 to 17.
"The typical situation that we are faced with is where the young person gets very irritable and aggressive when they're asked to clean their rooms, do their homework or to come to dinner when they really want to finish their game," Fisher said.
Their brains are being orientated to the point where their capacity to delay gratification has been diminished radically.
"Classic addiction symptoms are wanting to isolate themselves in their room and play games all day. Any distraction from the addiction and they become hostile and impatient," he said.
"Other symptoms are poor concentration, not eating enough, not brushing their teeth or even bathing," he said.
He said that weaning children off computer games involves parents setting ground rules such as limiting the number of hours a day that they can play and making clear that any misbehaviour will lead to a week-long ban.
"The parents also have to learn to deal with the aggression of the young person because often their anger holds the whole family hostage," he said.
"A lot of parents want peace and quiet and the child learns that by being angry, they'll get their own way. We train parents to hold the boundaries," he added.