Neuropharmacologist David Nutt, MD, of Imperial College London, and colleagues rated 20 different drugs on a scale that takes into account the various harms caused by a drug. Drugs are rated on nine harms a drug causes an individual and seven harms a drug causes society.
The scale, developed by a panel of experts called the Independent Scientific Committee on Drugs (ICSD), ranges from 0 (no harm) to 100 (greatest possible harm). It is weighted so that a drug that scores 50 is half as harmful as a drug that scores 100.
"The highest and lowest overall harm scores … are 72 for alcohol and 5 for mushrooms," Nutt and colleagues calculate. "The ICSD scores lend support to the widely accepted view that alcohol is an extremely harmful drug both to users and to society."
Alcohol was found to be the most harmful drug to society and the fourth most harmful drug to users.
The findings should come as no surprise: Alcohol has been linked to more than 60 diseases.
"Alcohol does all kinds of things in the body, and we're not fully aware of all its effects," alcohol researcher James C. Garbutt, MD, of the University of North Carolina at Chapel Hill, recently told WebMD. "It's a pretty complicated little molecule."
Alcohol vs. Heroin, Other Drugs
Using the ICSD ratings, Nutt and colleagues rated 20 substances in terms of the overall harm they do. Their results:
|Benzodiazepines (e.g. valium)||15|
|Mephedrone (aka drone, MCAT)||13|
Heroin, crack, and crystal meth were the most harmful drugs to the individual, while alcohol, heroin and crack were the most harmful to others.
According to this "multicriteria decision analysis approach," alcohol is almost three times as harmful as cocaine or tobacco.
Nutt and colleagues conclude that aggressively targeting alcohol harm is “a valid and necessary public health strategy."
In an editorial accompanying the Nutt team's report, Jan van Amsterdam of the Netherlands National Institute for Public Health and the Environment and Wim van den Brink of the Amsterdam Institute for Addiction research note that the legal penalties prescribed by various nations’ drug policies are out of synch with the actual harms caused by different drugs.
"It is intriguing to note that the two legal drugs assessed -- alcohol and tobacco -- score in the upper segment of the ranking scale, indicating that legal drugs cause at least as much harm as do illegal substances," van Amsterdam and van den Brink write.
The editorial and the Nutt study appear in the Nov. 1 Online First edition of The Lancet.