As pester power kicks in and the computer games' industry launches its latest products on to the Christmas market, Panorama hears from youngsters who've dropped out of school and university to play games for anything up to 21 hours a day. They describe their obsessive gaming as an addiction. Reporter Raphael Rowe, meets leading experts calling for more independent research into this controversial subject, and reveals the hidden psychological devices in games that are designed to keep us coming back for more.