The following chart shows the classifications of drugs as proposed in the UK Misuse of Drugs Act 1971. Class A substances being the most harmful and class C drugs being the least harmful. The penalties attributed to the drugs are also determined by the class of drug used.
The mean harm score based upon the scoring of independent experts is presented below. As can be seen, the current classes of drugs do not correlate with the scores attributed to the drugs by medical professionals and the scientific literature used in this meta-analysis.
The below chart is scored from 0-3, with 0 being no risk,
1 some, 2 moderate, and 3 extreme risk.
If we assume that the results of this study are an accurate representation of the apparent harm of the drugs studied, obviously, the current classification system is not objectively based upon the physical harm, societal harm, or addictiveness of the drugs.
Sometimes people are too quick to jump to conclusions when certain drugs are proposed to be legalized, cannabis being one example. What is needed are more objective studies that get rid of the political baggage so that we can actually make informed decisions about the dangers of drugs.
Development of a rational scale to assess the harm of drugs of potential misuse
The Lancet, Volume 369, March 24, 2007, Issue 9566, Pages 1047-1053
D. Nutt, L. King, W. Saulsbury, C. Blakemore