[pasta]

Not exactly an answer to your question, but some years ago (2010) this report was made in the UK about the Harm Caused By Drugs:

http://media.economist.com/sites/default/files/imagecache/or...

Edit: here another chart showing the 'dependence' of tobacco is very high:

http://medicalmarijuana.procon.org/files/1-medical-marijuana...