Well, I can only speak about cigaretts:
I am a smoker. And I had quitted three times but each time started again.

Now, the last time I started again (I did so because I was so depressed because a girl I liked had gotten a new girlfriend), after the first cigarette, I wasn’t addicted again. Also not after the second. - But the more you smoke after you have quitted again, the faster you get addicted again.
Now I can’t really say if you can compare to that alcoholism. - But I think it might be similar there.