We should clearly be focusing more on why people do these harmful drugs in the first place, and prevention of it than throwing them in dumps for the rest of their lives.
It's theorized that the quest for mind-alternation is the fouth drive, like the drive to have love. I can't find a reputable source explaining it at the moment, but heres a short summary.
Psychopharmacologist Ronald K. Siegel refers to intoxication as the "fourth drive", arguing that the human instinct to seek mind-altering substances (psychoactive drugs) has so much force and persistence that it functions like the human desire to satisfy hunger, thirst and the need for shelter.[1]
Once more. Drugs are only harmful if over excessively used. If anyone has any sort of self control they should be alright. Throwing their lives in the dump would be pitiful due to the fact that that would probably already happen. Drugs only enhance what you are. Doing drugs doesn't instantly throw your life away.
This is not entirely true. Many drugs have a very, very small window of effect before death and can be easily overdosed on. Addiction also plays a factor, you can become addicted to strong drugs after just one use. Your addiction can drive the amount you need to achieve craving satisfaction above the lethal limit.
For example, a hallucinogen not too different from LSD was synthesized somewhat recently called Bromo-DragonFLY. While this drug is non-addictive, it is only slightly less potent than LSD (LSD is extremely potent, if you were unaware you generally ingest a very tiny ammount, measured in µg) and can be easily overdosed on. Bromo-DragonFLY is currently legal in the USA, but not recomended.