Does each “buzz” give a different effect? How does the brain know which part to let the serotonin into to get a specific high? Like is there the same “buzz” between lets say alcohol, coke, heroin, gambling, cigarettes, weed or painkillers? How does your brain know how to let loose the “high” part? How does a alcoholic different from a alcoholic or gambling addict? Is there like a thin line that runs through all addictions? And this is why so many fall under the very vague umbrella of just addicts?? Can explain more if need be.
The Pleasure Compass is a great read on this topic.
The highlight I remember is that the Ventral Tegmental Area (VTA) was a center piece.
Different substances / behaviors come with different physical damage. As far as which parts constitute the addiction itself… that’s super hard.
The question you’re asking is an insanely complicated one that blurs lines between biology, psychology, and will itself. Maybe identity too.