When I was disfellowshipped, I was told by the judicial committee: "God no longer loves you, not for what you do, but for who you are" (exact words). I walked away from the Kingdom Hall believing it. I figured, if I'm some sort of practical joke put on earth by God, then I might as well go out partying. My drinking increased exponentially, and I began using every sort of drug imaginable. I nearly died. Initially, the drugs did what they were supposed to do by providing me escape, but eventually they turned on me. My life eventually revolved around when/where/how I was going to get my next drug. I used alcohol to counteract the effects of the drugs I was taking when I needed to sleep (read: pass out). When I needed to wake up, I used drugs to counteract the effects of the alcohol. I am happy to say that I have been free of alcohol and drugs for 16 years.
If you believe that you can exercise self-control with drugs, more power to you. Please just remember that they alter your conscious state (why take them if they didn't?), and can give you a false sense of reality. The decision making process can become convoluted. If you consciously decide to choose drugs, please make sure you have a means by which you are able to stop. Drug abuse is so prevalent in today's world because most people think they can stop any time. They do not understand the nature of addiction.
Having said that, I will say that I am in favor of the legalization of certain drugs for medicinal purposes. I am an advocate of medical marijuana. If drugs are prescribed by competent physicians for specific ailments, I see no reason to restrict their sale.
However, keep in mind that if recreational drugs are legalized, they will also be regulated by the federal government. This means that they will be taxed to death, like alcohol and tobacco. While possession will be decriminalized, those who can least afford them once they become legal will become the same ones who will use them most. This will lead to a dramatic reduction in drug-related offenses, but may likely lead to increased petty crimes such as theft and burglary. Imagine being the owner of your local convenience store, now stocking legal marijuana cigarettes! If I were that shopkeeper, I'd have to hire round the clock armed guards! Case in point: Cigarettes have become so highly taxed in parts of Canada that convenience stores there now keep their cigarettes in locked steel cages!