Is it possible to use drugs responsibly?

This study in the Lancet, led by a former adviser to the British government on drug policy, ranks 20 drugs according to their harm:



Alcohol tops the list, beating both heroin and cocaine for combined harm to both society and users. Tobacco also turned up high on the list, as well as Cannabis--which is surprisingly high up when you consider the fact that drugs like ketamine, MDMA and amphetamines are either below or around it.

So, my question is this, is it possible to use drugs responsibly? Also, how ought each drug's ranking affect policy? Should drugs which almost exclusively harm the user be openly available? After all, if it doesn't harm anybody else. . . Should we be taking a different approach besides criminalisation to tackle the social harm from drug use?

I personally believe that drugs can be used responsibly, but there are some drugs that I wouldn't recommend anyone ever do, not even once. I'm pretty tame when it comes to putting things into my system; I drink rarely (Don't even enjoy it), and smoke weed occasionally, but that's pretty much it. I'd try mushrooms if given the chance but it hasn't come up yet. I don't see too much of an issue with the way I handle myself.

With proper education and respect of the drug, you can use it responsibly, even to the point that you decide not using it at all is the best choice.

Take alcohol as an example. While alcoholism is a concern, it is a minority among the millions of people who go out drinking every weekend who are affected by it, despite being a Class A if it were made illegal (Due to the damaging effects it has on you and others around you). The cause of that can be down to the fact that Secondary schools (at least in the UK and I assume elsewhere) teach about the effects and potential dangers of abusing alcohol at an early age, as well as illegal substances (although from what I've experienced alcohol is warned about far more often than illegal drugs, likely because you're at a higher chance to be exposed to it). Same goes for tobacco, which goes even further to have governments restricting the use of it.

What I don't know (Full text behind a pay-wall) is if the study was conducted fairly, i.e. the effects of a drug on yourself or others as a pure sample. While it's obvious Heroin is a highly addictive and dangerous substance, I believe it would cause less harm to yourself if it was pure, rather than whatever the fuck street peddlers have cut in which is also not in your best interests to inject. I also have no idea how far the statements cover. Does harm to myself count if I fell over drunk, or others if I crashed my car drunk or stole money to feed my addiction?