Drugs such as alcohol and cocaine are detrimental to both individual users and society. David Nutt and co-workers, Imperial College London, UK, have used a multicriteria decision analysis approach to quantify how harmful a drug is by assigning a score out of 100. Sixteen criteria were indentified, nine relating to the harm that the drug poses to the individual, including mortality, dependency, impairment of metal function, and damage to relationship. The other seven criteria represented harm done to others, including injury, crime and damage to the community, both domestic and international.

Using this model, the most harmful drugs to an individual are (with part scores):

1. Crack cocaine (37)
2. Heroin (34)
3. Metamfetamine (32)

To society and others, the most harmful drugs are (with part score):

1. Alcohol (46)
2. Heroin (21)
3. Crack cocaine (17)

When all criteria are taken into account, the overall scores are:

1. Alcohol (72)
2. Heroin (55)
3. Crack cocaine (54)

• Drug harms in the UK: a multicriteria decision analysis
  D. J. Nutt, L. A. King, L. D. Phillips,
  Lancet 2010, 376.
  DOI: 10.1016/S0140-6736(10)61462-6