You might need mental help if you believe that WOW can enter your blood stream and cause a dependency. I'm sure that you perhaps meant that It could cause physical strain caused by hours of game play? or something similar?
. If so then Not the same thing sorry. A physical addiction would be when your body becomes accustomed to having foreign substances and then you suffer the withdrawl effects when it is no longer introduced such as vomiting,shaking etc.
Sooooo before you disagree with my comment think seriously about it first.
Edit:
That is very interesting. Could you point me to that health article?