British researchers evaluated the dangers of 20 substances -- including alcohol, marijuana, ecstasy, heroin and cocaine -- according to a set of 16 categories of harm. Of the 16, nine categories relate to the harm a drug does to the individual, such as early mortality, physical damage and substance dependence. Seven categories relate to social harms felt by others, such as crime and economic costs, both in the U.K. and overseas.
Trouble in a Bottle
Scoring highest, alcohol was the most harmful drug compared to others in the study -- and by a wide margin. Part of the reason for this stems from the law of large numbers, professor David Nutt of London's Imperial College, who led the study, explained in a BBC interview. Because alcohol is so widely used, it has a huge impact on society. Alcohol scored 46 in the study's damage assessment system, followed by a distant second, heroin (21). In third place was crack cocaine (17), with tobacco, cannabis and cocaine rounding out the highest six.
Alcohol, with an overall score of 72, was judged to be most harmful, followed by heroin at 55, then crack cocaine with a score of 54. LSD, buprenorphine, and mushrooms had the lowest overall scores.
"Our findings lend support to previous work in the UK and the Netherlands, confirming that the present drug classification systems have little relation to the evidence of harm," the study authors write. "They also accord with the conclusions of previous expert reports, that aggressively targeting alcohol harms is a valid and necessary public health strategy."
Nutt was sacked as an adviser to Britain's last Labor government for challenging official policy to boost the threat level of cannabis. He also suggested ecstasy should be downgraded, Time magazine reports. "By legislating on a substance without reliable scientifically-based evidence, we run the risk of causing more harm through criminalising users than might be caused by the drug itself," Nutt writes in his blog. "The evidence on drug harms should not be sacrificed for political and media pressure."
In the U.S., the economic cost of alcohol abuse totaled $184.6 billion in 1998, according to estimates from the National Institute on Alcohol Abuse and Alcoholism. That was more than the estimated cost of all illegal drugs combined -- $143.4 billion -- during the same year, although drug-abuse costs are growing more quickly than alcohol costs.