My understanding is that if one has a very strong urge to do something (I assume harmful)and cannot resist, that would be called an addiction. If one endulges, say, in drinking a cup or 2 of wine on Shabbos, and does NOT feel he /she NEEDS to drink, or NEEDS “just” one more drink, or NEEDS to drink during the week whenever the urge strikes, that wouldn’t be an addiction.
An urge is just that- a ta’ava. If one feels it is close to impossible to overcome the impulse, maybe it’s time to speak to someone wise and objective (mentor etc)