Illegal Drugs and the Analysis of Harms By Prof David Nutt

Posted on: June 20, 2019
Last Updated: November 24, 2023

David Nutt is currently the Edmond J. Safra Professor of Neuropsychopharmacology and director of the Neuropsychopharmacology Unit in the Division of Brain Sciences. In addition to several prestigious appointments in the past, David is currently Chair of DrugScience (formally the Independent Scientific Committee on Drugs (ISCD) and President of the European Brain Council. He has edited the Journal of Psychopharmacology for over two decades and acts as the psychiatry drugs advisor to the British National Formulary. David  broadcasts widely to the general public both on radio and television including BBC science and public affairs programs on therapeutic as well as illicit drugs, their harms and their classification.  He has published over 400 original research papers, a similar number of reviews and book chapters, eight government reports on drugs and 27 books. 

Author Quotes: 

The hysteria around cannabis (…) is largely a politically motivated campaign to avoid the politicians having to grapple with the real problem in Britain in terms of harms of drugs which would drip with the problem of both alcohol and tobacco – and that was not something the Government wanted to hear, largely because they have got a lot of money from the alcohol and tobacco industries.

In the British Misuse of Drug Act and the UN conventions and in the Australian Misuse of Drug Act, there is no definition of what a drug is and that is a major problem – because basically drugs are controlled arbitrarily by individuals that make up the definition.

Summary and slides: 

Professor David Nutt introduces the first of a series of video clips on his presentation and begins by commemorating the time he was relieved of his job due to the public hysteria around cannabis 10 years ago. 

He proposed his own definition of a drug, providing some colorful examples.

On a more serious note, he questioned why we care about drugs, drug harms and the control of drugs. 

In the 1990s, Viscountess Runciman set up a committee to evaluate the British drug laws and asked Professor Nutt to teach them about the relative harms of drugs. 

He came up with the nine-point scale of the relative harms of drugs, which was divided into three components. Professor Nutt refers to a systematic analysis that evaluated the different harms associated with controlled and legal drugs, highlighting the lack of correlation between controlled drugs under the Misuse of Drugs Act and their harms. 

He ends this video excerpt explaining how Larry Phillips suggested an MCDA (multicriteria decision analysis) approach to better the analyses of assessing drug harms.  Take-home Points: 

  • The nine-point scale of the relative harms of drugs had three components; each variable was given a score of zero to three. 
  • The study by Nutt et al. was the first systematic analysis to compare drugs that are controlled under the Misuse of Drugs Acts and non-controlled drugs. 
  • MCDA (multicriteria decision analysis) is an approach that deals with complicated decisions that cover variables that are measured in different ways. 


Learn more

  1. MCDA data analysis to inform drug policy by Prof David Nutt
  2. Post-Multicriteria Decision Analysis (MCDA) analysis of drug-related harms – Prof David Nutt
  3. Psychedelic therapy and synthetic alcohol – future treatments? – Prof David Nutt
  4. Alcohol – New Therapeutic Approaches and the Burden of Harm – Prof David Nutt
  5. Multi-Criteria Decision Analysis (MCDA) to evaluate drug-related outcomes By Prof David Nutt