It has nothing to do with whatever is "causing" the alleged "addiction". If it wasn't gaming or chatting, it would be something else that they are obsessed with. Yes, obsession, not addiction to anything. It's not the thing causing the problem. The person had the problem in the first place and the internet is just one of the targets of that obsession. It's just funny that the quacks that want this in the book haven't noticed that most of the people had some other "addiction" (obsession to something else) before the "internet addiction" was "diagnosed".