The Associated Press article title “Study: Alcohol more lethal than heroin, cocaine” succeeded in getting me to click through to the article. When I did, I wasn’t surprised to learn that the study in question didn’t actually find alcohol to be more lethal than heroin. What it concluded was that alcohol is the most harmful drug (out of 20 studied) when harms both to users and to those around them are tallied.
The study — authored by David J. Nutt, Leslie A. King, and Lawrence D. Phillips and published in The Lancet — used multicriteria decision analysis modelling to assess the harms caused by 20 different drugs used in the UK. During a one-day interactive workshop, members of the Independent Scientific Committee on Drugs (“a new organisation of drug experts independent of government interference”) met to score drugs on 16 criteria and weight the criteria based on their relative importance. The criteria considered harms to both individual users and to others — with the “others” category including society as a whole as well as those directly influenced by drug users. The 16 criteria fall into five categories:
- Physical harm to users: Drug-specific mortality, drug-related mortality, drug-specific damage, drug-related damage.
- Psychological harm to users: Dependence, drug-specific impairment of mental functioning, drug-related impairment of mental functioning
- Social harm to users: Loss of tangibles, loss of relationships
- Physical and psychological harm to others: Injury
- Social harm to others: Crime, environmental damage, family adversities, international damage, economic cost, community
The criteria definitions paint a disturbing picture of the many ways drugs harm both individuals and society. Mortality can be caused directly by a lethal dose of a drug, or indirectly by lung cancer or car crashes. Drugs can cause specific damage, like cirrhosis, or lead to related damage, like an HIV infection from sharing needles. Drug users may be more likely to perpetrate domestic violence or cause deadly car crashes, and some drugs can lead to an increase in acquisitive crime. Drug use can contribute to family breakdowns and decline in a community’s social cohesion and reputation. The production of drugs can cause local environmental damage (e.g., from meth labs), and international damage through deforestation and international crime. The direct economic costs – health care, police, social services, etc. – and indirect costs, such as loss of productivity, can add up quickly.
Using this methodology, the study found alcohol to be the most harmful drug, and cannabis the eighth. The top ten are ranked as follows:
- Alcohol
- Heroin
- Crack cocaine
- Metamfetamine
- Cocaine
- Tobacco
- Amfetamine
- Cannabis
- GHB (γ hydroxybutyric acid)
- Benzodiazepines
The authors also report which drugs were the most harmful to users and to others, when the groups are considered separately:
The most harmful drugs to users were heroin (part score 34), crack cocaine (37), and metamfetamine (32), whereas the most harmful to others were alcohol (46), crack cocaine (17), and heroin (21).
Because scores and weights were decided over the course of a single day by a relatively small (15-member) group of experts, it’s possible that a different group could come up with different results — although the authors note that their results are similar to those from similar analyses in the UK and Netherlands and correlate highly with objective data on health and economic costs.
The important takeaway from the study isn’t the exact numerical scores, but the observation that current UK drug policy doesn’t reflect the relative harms of different drugs. The study was funded by the nonprofit Centre for Crime and Justice Studies, and that organization’s press release emphasizes that “the relative harms of legal drugs such as alcohol and tobacco are greater than those of a number of illegal drugs, including cannabis, LSD, and ecstasy.”
The study doesn’t recommend specific drug-policy reforms, and study author Leslie King told the Associated Press alcohol is too embedded in our culture to prohibit successfully. I do hope that such research might inform drug sentencing practices, though. For instance, I suspect multi-year jail terms for possession of marijuana — which exact heavy tolls the individuals, their families, and their communities, as well as on taxpayers who pay for incarceration — are often more harmful than pot smoking.