[digi_owl]

In essence, addiction is many things rolled up in a single term.

Yes, it is a chemical reaction inside the brain. But over time that chemical reaction gets padded by conditioned reflexes. This to the point that one may find some relief by mimicking the actions related to the chemical reaction.

The real crazy stuff comes when it becomes harder to kick those conditions reflexes than the chemical addiction itself. Meaning that the body no longer craves the chemical, but still react to external stimuli by attempting to go through the actions related to taking the chemical.

[girvo]

As an example: when I was an addict, and was in severe withdrawals, I would go through the motions and inject saline solution. This would, despite me knowing it's not actually a drug, get rid of my withdrawals for a while; the placebo effect coupled with the "ritual" is very powerful. After I got clean, and the cravings went away, I would still have dreams of injecting drugs; not heroin, but anything. The behaviour was an addiction in and of itself.

[rokhayakebe]

This is a great insight; the behavior is an addiction just as much as one can be addicted to the substance.