I never became addicted to alcohol, but I have become addicted to si. I know I can drink regularly for a time, then drop it because I simply do not want it. I can go weeks or months without picking up a drink (socially or otherwise), but I can't necessarily do that with si. I think it has a lot to do with the effects of either coping skill. If you are easier able to find an alternative coping skill or it doesn't work much, much better than another coping skill, it doesn't have a psychological need to become an addiction. (I tend to believe we only get addicted to things that bring about an immediate, intense, and very reliable positive effect - even if the negative effect comes quickly afterwards). I know it's not necessarily the way most people look at addiction, but I think it happens with drugs that are addictive after the first time... if the effect (positive) wasn't SO great (either physically or psychologically). then we would not seek it out again when there are viable alternatives that can bring a greater positive effect... For me, si brings a much greater positive effect than alcohol does, so I will want to reach for it before I reach for a drink. Even with the negatives associated with my si, the immediate positive effect often times out-weighs any consequences...
after writing all that out, I'm wondering if I read you wrong, do you mean not addicted to alcohol either? because that's a good thing

There's no rule that says there must be an addiction to a coping skill or substance. I think it just can get that way for a lot of people, and we end up hearing about that. I was not addicted to si for the first 18 years I did it. Then I changed spots again, and I happened to become addicted because of the impact and the stressors I was facing at the time. I also think an addiction can be left behind if the conditions are right...