In July this year I gave a lecture on the assessment of drug harms and how these relate to the legislation controlling drugs. According to Alan Johnson, the Home Secretary, some contents of this lecture meant I had crossed the line from science to policy and so he sacked me. I do not know which comments were beyond the line or, indeed, where the line was, but the Government has lost its major expert on drugs and drug harms and may indeed lose the rest of its scientific advisers in the field.

All drugs are potentially harmful and many of the harms can be measured. We can use scientific methods to estimate these and produce a ranking, and compare our scores with their location in the Misuse of Drugs Act. Heroin and cocaine appear to be in the correct place (Class A), whereas Ecstasy (Class A) and cannabis do not (Class B).

The reason for making drugs illegal is to let society reduce harms by punishing their sale and use. The purpose of having the ABC classes is to scale penalties according to relative harms. Possession of a class A drug for personal use can lead to seven years in prison, for class B, it is five years and for class C, two years.

The classes are also important in educating the public about the relative harms of drugs. So it is imperative that the classification of drugs truly reflects their harms, otherwise injustices may occur and the educational message be undermined. Scientific inquiry into drug harms must also be honest and accurate so that the best quality evidence is available to the experts and government. Legal drugs such as alcohol and tobacco are as harmful as many illegal drugs and currently score highly on our ranking list.

What are appropriate penalties for drug use? This question has moral and practical aspects, but the penalties must reflect the real and relative harms of drugs.

My sacking has cast a huge shadow over the relationship of science to policy. Several of the science experts from the Advisory Council on the Misuse of Drugs (ACMD) have resigned in protest and it seems likely that many others will follow suit. This means the Home Office no longer has a functioning advisory group, which is very unfortunate given the ever-increasing problems of drugs and the emergence of new ones. Also it seems unlikely that any “true” scientist — one who can only speak the truth — will be able to work for this, or future, Home Secretaries.

Others have suggested a way forward: create a truly independent advisory council. This is the only realistic way out of the current mess.

Prof David Nutt was chairman of ACMD

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