An ounce of NSFW might help here. There's a very reasonable definition of addiction using ΔFosB modulation. Scott probably doesn't like this because it implies that the concept of addiction is hopelessly overlapping with desires for food, shelter, exercise, social belonging, etc. and totally avoids the difficult subjective task of determining whether a person's addiction is interfering with their daily life; Scott gets paid good money to be judgmental about his patients' lives!