David Nutt spells out the terrible consequences the War on Drugs has had on medical science:

There were six trials of LSD as a treatment for alcoholism, the last one in 1965. The evidence is it's as good as anything we've got, maybe better. But no one is using it for this. I wonder how many other opportunities have been lost in the past 40 years with important drugs, like MDMA (ecstasy) and its empathetic qualities or cannabis for all its possible uses and insights into conditions like schizophrenia. All those opportunities have been wasted because it is virtually impossible to work with a drug when it is illegal.