i don't think addiction and dependance are the same thing. some people are dependent on Blackberry devices to perform their job, and for some people on Blackberry devices, it is their only means of communication (if they are on business trips). For people in the office who are dependent on Blackberry devices for Calendar meeting reminders, well if the Blackberry stops working, it is a hassle. It decreases productivity and forces people to set other forms of communication up. Meeting requests can no longer be accepted on the fly, and planning for things becomes difficult. For an emergency meeting for the new product line comes up and a meeting request needs to be sent out to 30 people in different departments and different parts of the country...well if the Blackberry is not working then people might not get the meeting request in time. You would have to manually call up every single person.
Thing is...I wouldn't necessarily call it an addiction and that it "ruins relationships." Yes, when you have a toy you are more likely to play than if you don't have a toy...that is correct. But fiddling around with your Blackberry while on the train into work is perfectly acceptable as listening to your ipod or reading the paper. it's something to do to kill time.