Alcohol and tobacco ‘more harmful than cannabis and ecstasy’

The present systems for classifying drugs in the UK and other countries have little relation to the evidence of harm, and they should be replaced by systems that facilitate the more aggressive targeting of alcohol harms, according to Professor David Nutt and his colleagues at the Independent Scientific Committee on Drugs in the UK.

In a paper published in the medical journal, The Lancet, Professor Nutt and his colleagues repeat the claims that in 2009 got him sacked by the then Labour government as chairman of the government’s Advisory Council on the Misuse of Drugs. The then Home Secretary, Alan Johnson, demanded Professor Nutt’s resignation on the grounds he had lost confidence in him as an impartial adviser to the government. Mr Johnson said that Professor Nutt could not be an adviser to government while simultaneously campaigning against government policy, in particular for advocating a ‘softer’ line on cannabis than the government was inclined to take. (See UK Alcohol Alert Winter 2009)

The new paper in the Lancet re-works the arguments that Professor Nutt and colleagues have been advocating for some years. In the paper, they identify three main factors that together determine the harm associated with any drug of potential abuse:

• the physical harm to the individual user caused by the drug

• the tendency of the drug to induce dependence

• the effect of drug use on families, communities, and society

Within each of these categories, they recognized three components, leading to a comprehensive 9-category matrix of harm. Expert panels then gave scores, from zero to three, for each category of harm for 20 different drugs. All the scores for each drug were combined to produce an overall estimate of its harm. Alcohol and tobacco ‘more harmful than cannabis and ecstasy’

In order to provide familiar benchmarks, for comparison with illicit drugs, five legal drugs of potential misuse (alcohol, khat, solvents, alkyl nitrites, and tobacco) and one that has since been classified (ketamine) were included in the assessment.

The process proved simple, and yielded roughly similar scores for drug harm when used by two separate groups of experts.

The new ranking placed alcohol and tobacco in the upper half of the league table. These socially accepted drugs were judged more harmful than cannabis, and substantially more dangerous than the Class A drugs LSD, 4-methylthioamphetamine and ecstasy.

Heroin, crack cocaine, and metamfetamine were ranked the most harmful drugs to individuals, whereas alcohol, heroin, and crack cocaine were the most harmful to others. Overall, alcohol was the most harmful drug, with heroin and crack cocaine in second and third places.

Professor David Nutt, lead author on the paper, said: “Drug misuse and abuse are major health problems. Our methodology offers a systematic framework and process that could be used by national and international regulatory bodies to assess the harm of current and future drugs of abuse.”

Professor Colin Blakemore added: “Drug policy is primarily aimed at reducing the harm to individual users, their families and society. But at present there is no rational, evidence-based method for assessing the harm of drugs. We have tried to develop such a method. We hope that policy makers will take note of the fact that the resulting ranking of drugs differs substantially from their classification in the Misuse of Drugs Act (in the UK) and that alcohol and tobacco are judged more harmful than many illegal substances.”

Reaction

Publication of the Lancet paper generated extensive media coverage, not only in the UK but also internationally. A common feature of the coverage however was that the media appeared to misunderstand the message of the paper, headlines frequently stating that ‘experts had found alcohol to be more dangerous than heroin or cocaine’. In reality, the conclusions of the paper are more ambiguous than these headlines suggest. The key to the ambiguity is that the paper distinguishes between the dangerousness of a drug, in respect of the risk of harm to the user, from its harmfulness, the damage its use inflicts on people other than the user and on the wider society.

As can be seen from the graph, the paper clearly ranks alcohol as less dangerous to the user than heroin or cocaine, though it is more harmful overall because of the damage inflicted on third parties and the wider society. Presumably, however, the amount of damage to others is a reflection of how extensively any given drug is in use in any given society, and, as some critics pointed out, if cocaine were used as extensively as alcohol the picture might look different. Indeed, in an earlier paper Professor Nutt and his coauthors themselves explained that “direct comparison of the scores for tobacco and alcohol with those of the other (illegal) drugs is not possible, since the fact that they are legal could affect their harms in various ways, especially through easier availability”.

Another, more fundamental criticism, perhaps, is that Professor Nutt’s ranking system gives a spurious air of scientific objectivity to a system which in reality is as subjective and arbitrary as the classification system it is intended to replace. Critics suggest that weighing different kinds of harm against each other is always going to be an exercise in comparing apples and pears. If, as reported, cigarette tobacco kills half the people who smoke it, ranking it as less harmful than alcohol is at bottom a value judgement rather than a scientific finding.

David J Nutt, Leslie A King, Lawrence D Phillips, on behalf of the Independent Scientific Committee on Drugs. Drug harms in the UK: a multicriteria decision analysis. Lancet 2010; 376: 1558–65