system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: To what extent is drug addiction physical and to what extent is it psychological?

It is known that people who take drugs tend to be unsuccessful and in bad shape. But I am now wondering, are they mostly in bad shape due to taking drugs or mostly taking drugs due to being in bad shape? If you force a conventionally successful person into taking drugs, would they be as bad as typical addicts or would it be relatively easy to quit? (I suppose it varies a lot depending on drugs)
gpt
Actually, most drug users are considered functional.  Addiction is the rarity, not the norm - something that should be obvious once you consider alcohol and tobacco (both drugs).

Nor is addiction as all-powerful as it is normally portrayed.  Certain drugs - heroin and alcohol amongst them - can cause physiological changes that make it dangerous to quit cold turkey.  Nicotine isn't dangerous to quit, but your body will object when you try.  Drugs like marijuana and cocaine have no real physiological side effects - if you quit, then you stop taking the drug and your body doesn't notice.

Most of the reason for continuing addiction is psychological.  However, even this isn't as potent an effect as people commonly assume.  The reason you see such awful statistics on relapses is that they're talking about people with an addictive pattern of behavior.  If you're talking about the population at large, the overwhelming majority of people quit and move on with their lives without much hassle.

So if you took someone with no real addictive proclivities and fed them drugs, you might have to wean then off the drugs (for certain drugs) but the most likely result is that they'd just continue on with their life post-drugs.