Both smoking and cutting are self destructive, that is true. The difference is that smoking is not being used as a punishment on yourself. If you are upset about something, you don't think, hey, I hate myself, I think I'll go smoke a cigarette and hope I get lung cancer later on. Smoking is a habit, thats true, but the mindset is different.

Most cutters or other SI behaviors come with depression, anxiety and often the person is not functional. Smoking may use the nicotine and be addicted to it, but smoking does not necessarily mean that you are depressed. Take a high school kid who starts smoking because its cool or they want to fit in with their friends. After a while it becomes a habit, and while it may cause lung cancer later on, the reason for smoking was not to hurt themselves. The problems smoking cause are just effects of the behavior. People who SI are trying to injure themselves immediately and that is the whole purpose of doing it.

I don't know if that came out the way I wanted it to, but its as close as I can do to explain the difference.

Sam2