There have been many attempts to understand and explain addiction and an interesting explanation is that of Dennis Wier.
Dennis say addiction is a trance within a trance, and as we come out of the first trance we are precipitated into the second trance, and as we come out of the second trance, we are precipitated back into the first trance. And so round and round we go, with no way out.
The advantage of this explanation is that it seems to account for the facts, and it accounts for the various kinds of addiction, and it may offer a way out.
We can find Dennis Wier on http://www.tranceresearch.org/b284/?page_id=6