Drug Harms in the UK: A Multicriteria Decision Analysis (The Lancet, 2010)
In 2010, David Nutt and colleagues published a multicriteria decision analysis (MCDA) of 20 drugs in the UK, scoring each on 16 criteria grouped into harm to users and harm to others. The study used independent experts scoring each drug on a 0-100 scale across criteria including mortality, dependence, mental impairment, injury, crime, economic cost, and community damage.
The results were striking: alcohol scored 72 overall (highest), followed by heroin (55) and crack cocaine (54). Mushrooms scored 6 (lowest). Cannabis scored 20. The paper demonstrated that current drug scheduling bears almost no relationship to evidence-based harm assessment.
The study became one of the most influential papers in drug policy history. It provided a rigorous, transparent framework for comparing harms and exposed the incoherence of existing classification systems. Nutt had been fired from his government advisory role the previous year for making similar arguments publicly.
Key takeaways
- –Alcohol ranked as the most harmful drug overall when harm to others is included in the analysis.
- –Current drug scheduling in most jurisdictions does not correlate with evidence-based harm rankings.
- –The MCDA framework makes value judgments explicit and transparent, unlike legislative classification which obscures its reasoning.
- –Harm to others (family, community, economic) accounts for a large share of total drug harm — individual toxicity alone is insufficient for policy.
- –Psychedelics and cannabis consistently rank among the least harmful substances on evidence-based criteria.