Change of position - All drugs should be legal

[Dystopia]

Although I agree in principle to maximum liberty, I struggle with the idea of loosening markets to addictive drugs

The issue here is that what is addicting to someone might not be addicting to all of us. Even healthy acts like sex can become addictive. It is possible to become addicted to a lot of things. Many variables increase the likehood of addiction. There's also a difference between psychological and physical addiction. Heroin breeds physical addiction - Weed, from what my friends tell me, not so much, it's just the psychological need to feel high again that creates some sort of addiction. How are we going to determine what is addictive or not? Can I classify smartphone games as addictive as well? 

I find the argument from liberty unsatisfying when immediately following there is discussion about production and trade regulation. This ignores the fact that the safe production and dispensing of these drugs is already regulated to achieve the benefits that you listed (thinking of your heroin example). What you are really asking is for the existing regulations to make it easier for people to obtain them.

But there are more uses for any drug than those prescribed by doctors. Arguably, we should only drink one glass of wine or beer per day if we want to remain healthy, but most of us have got drunk. I don't think people use heroin to completely suppress all pain and phobia under medical supervision. you might use opiates to suppress unbearable physical pain, but there's certain limitations to it. Moreover, what is considered a benefit becomes subjective - For some people it might be to suppress pain, but for others it is the high, the things you can do while high, mere experimentation, etc.

I also think it's important to compare physical dependency rates and withdrawal symptoms when making broad comparisons to substances with less regulation (caffeine, alcohol, tobacco). Considering this, comparing heroin to tobacco and caffeine is a bit ridiculous. Alcohol on the other hand may be a fair comparison. I haven't done enough homework to be definitive in this regard.

Well, you hit the nail - If we're going to criticize heroin we must understand alcohol can kill you with mere withdrawal symptoms, something not all drugs can efficiently do when you quit cold turkey. Arguably, tobacco kills people because of health risks and alcohol kills and hurts people because of behaviors and actions that result directly or indirectly from alcoholism and similar conditions. Both are negative effects about drugs we should address. If withdrawal symptom is a reliable indicator, then alcohol should be banned or more regulated than it is. If addiction and dependency is more important, then tobacco and nicotine would be banned right away if you consider the dependency rates.

The other aspect is the notion that it should be legal if nobody else is harmed. Again, I agree in principle; however, addiction of all types can have significant material impact on dependents. How could we ever monitor the 'no harm to others' idea? An argument claiming that drug use should be allowed because addicted gamblers and alcoholics neglect their families would be unconvincing.

Well, people neglect their families for a lot of reasons. You can neglect your family because you gamble constantly, or simply because you're an idiot. It doesn't matter either way - We can treat addictions if people are open to rehabilitation without banning behaviors or substances. Any addiction has material implications on dependents - Speaking as someone who smokes cigarettes, I do know that - But can have some control on the effects it has on other people. It's not illegal to smoke near schools where I live, but I don't do it because it would be irresponsible. I also don't smoke with non-smoker friends without asking if they mind (they usually don't). I occasionally get drunk (like many people) but I know I'm usually a very pleasing person when I'm intoxicated - I have friends who start fights and insult random people, I don't - And I also know when to stop.

I think the money spent policing illicit drugs would be more effectively used in education and rehabilitation programs. I also would have no problem voting for a referendum allowing marijuana use, but without a more compelling argument would vote no for a similar referendum for heroin.

I agree with the first part. However, note not everyone would start using heroin if you legalized it. Even light drug users are afraid of the consequences. Among recreational users, cocaine seems to be preferred for a spontaneous high because it doesn't create dependence right away (I've never tried it myself, but people seem to enjoy it).