This study comes up time and again but is really not founded very well. I couple of members of the Independent Scientific Committee on Drugs - whatever exactly that is - sat together and scored a selection of drugs on a selected set of criteria. That's it, there is really no data behind this study other than the opinions of those people. Those opinions might be correct but they may as well be biased or even totally wrong.
>Members of the Independent Scientific Committee on Drugs, including two invited specialists, met in a 1-day interactive workshop to score 20 drugs on 16 criteria: nine related to the harms that a drug produces in the individual and seven to the harms to others. Drugs were scored out of 100 points, and the criteria were weighted to indicate their relative importance.
You could make the scores come out however you wanted based on the people you chose for the "1-day interactive workshop" and the criteria you used as the basis for the analysis. This isn't something you'd ever want to use as a basis for policy.
> Overall, alcohol was the most harmful drug (overall harm score 72), with heroin (55) and crack cocaine (54) in second and third places.