I look at it both ways. I think for some it is a disease, For some it is behavioral.
When I look back when I was a teen I started to smoke a little because it was the cool thing to do with all of my cool friends. Well, when I reached the ripe old age of 20 I decided not to smoke anymore, so I just quit. Did I have a problem doing that.......not even one. When I have had past surgeries the doctors gave me pain meds. I took a few here and there and I didn't like how they made me feel. Suffered through most of my pain with extra strength tylenol because I refused the pain meds. So, why do some people get addicted to the pain meds and I didn't like them and didn't even want to take them? My daughter tells me that some people can pick up heroin and use it and put it down without a problem. Others are hooked from the start. She has seen this first hand.
Some have a disease and for others it is behavioral.