ANYTHING can become an addiction. I think that depends a lot on a person's personality and if they're prone to obsessive behavior.
I'm sure that for some people, cding is an addiction and/or obsessive behavior. For me, it is simply who I am though. Like I said - I'm only addicted to being me. I'm quite certain it is unhealthy for one to choose NOT to be who they are.
I believe that most cd's are not of the addictive personality type, just like most non-cd's are not of the addictive personality type. There is much diversity among people and that is also true within the cd community.