Using may be a self-harm. Acquisition is often not. And once use makes acquisition a problem, violence ensues. And even when it doesn't, the ability to defend oneself from the medical ravages against the body diminishes and the cost is places upon society. The society that chose, one way or another, to cut that off at the source.
Or attempt to.
Personally? I don't have much issue with the use of many (though not all) drugs, in and of themselves. But they aren't used in an isolated vacuum.
the ability to defend oneself from the medical ravages against the body diminishes and the cost is places upon society
The problem with that argument is that, not only is limiting it to drugs is arbitrary (why not convict the guy who becomes morbidly obese or extremely anorexic?), but I think it often is simply wrong, because it ignores the real alternative. The medical bills of an heroin addict may be expensive, but a guy who dies in his 60s from drug use is probably much cheaper if he had died in his 90s, possibly with some chronic condition.
Besides, imprisoning him is probably more expensive still, so it's cutting your nose to spite the face anyway.
If people are committing crimes to support their drug habit, you can just convict them for those crimes, so that doesn't justify criminalizing the acquisition.
Or attempt to.
Personally? I don't have much issue with the use of many (though not all) drugs, in and of themselves. But they aren't used in an isolated vacuum.