"Nutt and colleagues used three factors to determine the harm associated with any drug: the physical harm to the user, the drug's potential for addiction, and the impact on society of drug use.
The researchers asked two groups of experts -- psychiatrists specializing in addiction and legal or police officials with scientific or medical expertise -- to assign scores to 20 different drugs, including heroin, cocaine, ecstasy, amphetamines, and LSD."
Here are some of the rankings: (1 is the most harmful)
4. Street methadone
They also stressed the disruptiveness of the 'legal drugs', and hope to push for better regulation.
"Tobacco causes 40 percent of all hospital illnesses, while alcohol is blamed
for more than half of all visits to hospital emergency rooms. The substances
also harm society in other ways, damaging families and occupying police
If anyone comes across the full Lancet article, feel free to fill in the rest of the top 20 list.