That's the point I always consider: I'm also inclined to think that anyone, to be able to take drugs freely, should be responsible for the consequences, including support, treatment, medical cares in case of overdoses...

But then I begin to think about consequences of car crashes (be it to me or to someone else), about cigars. Some countries already treat that, assuming it's a thing that the society wants. And it easily goes to bed eating habits, and I think that the line goes too much to the other extreme.

Then I conclude that people from each country, each nation, or even each state/city, has a common sense on what is acceptable or not: the society from that circumscription decides when to pay for individual damages (treatment, support, etc), and for which source of damages.

If cars provide more benefits than costs, decide to support it. Drugs? No. Cigars? Yes. Nuclear power plants ? Yes. And so on....