MDMA used in treating PTSD
scientificamerican.com
scientificamerican.com
(Is there a stigma to putting cancer patients on morphine? No. But yet there is a stigma when someone wants to give them THC, or when psychologists want to use MDMA or LSD. Considering I can buy highly psychoactive drugs at Starbucks, I don't really understand it...)
From an ev-psych standpoint, medicine is considered to be a "gift" from a society to an individual, and yet certain drugs also lower the status of people who consume them, because of their association with "unproductive behavior." We don't want to allow, as a rule, gifts to lower the recipient's status, because we can be on the receiving end of a gift without being aware of it, and we have to act like we like it as part of a certain social dance. Thus, we ban potentially status-lowering gifts.
Note that alcohol, caffeine and other such "consumed as part of eating ritual" drugs, even if they did lower status, aren't part of the gift culture of medicine—that's why relatively few suggest banning them.
Where I am, on one of the many tips of Europe, the argument against drugs seems to revolve around risks, for example the potential long term effects of taking MDMA as it has been linked decreased cognitive performance, Parkinson (this later one has been disproven), etc...
In the US there is a huge stigma associated with weed, but in Canada people don't really care. The difference there comes from the official US government message that weed makes people insane and murderous, and the subsequent war on drugs. A good documentary to watch is "The History of Marijuana", which covers much of the post World War II period of the US government campaigning against Marijuana.
The Psylocibin ( http://en.wikipedia.org/wiki/Psylocibin )category is worth expanding, it has had the biggest resurgence in research.
"After the therapy, he vacationed in Jamaica, began dating a local woman and bought a house on the island. "I'm happy and well adjusted now," he says. "It's a good fairy-tale ending. As soon as we get some little Bob Marley kids it'll be even better.""