Scientific interest in the multibillion dollar computer games industry has mushroomed in recent years, after teenagers in several countries killed themselves and others after playing violent games. Various governments have put pressure on the industry to add a health warning to games packages. But many players actually described themselves as addicts, said Stephen Kline, a social psychology professor and media analyst at Simon Fraser University.

Heavy games players can play an average 17 to 26 hours a week. The online games, in which players battle with opponents online, are considered the most gripping and time-consuming. Children from the age of 10 are now starting to play online games, he said, and families should know it is radically different from comics.