'Alcohol most dangerous drug to society' - Prof Nutt

Alcohol is more harmful than heroin or crack, according to Professor David Nutt, the former UK chief drugs adviser.

Prof Nutt co-authored a report published in medical journal the Lancet which ranks 20 drugs on 16 measures of harm to users and to wider society.

Tobacco and cocaine are judged to be equally harmful, while ecstasy and LSD are among the least damaging.