Psychoactive drugs of misuse: rationalising the irrational.

972 www.thelancet.com Vol 369 March 24, 2007 Ideally, policy responses to psychoactive drugs of misuse would take into account the variations in harm that each kind causes to users and the community. In today’s Lancet, David Nutt and colleagues show that the UK classification of psychoactive drugs into three categories of harm (A, B, and C) is only modestly correlated with expert ratings of the harms caused. They also point out the obvious: the classification excludes the psychoactive drugs whose use causes the greatest harm—ie, alcohol and tobacco. Nutt and colleagues asked UK experts in psychiatry, pharmacology, and addiction to rate drugs on three major dimensions of harm: physical health effects, potential for dependence, and social harms. The experts showed reasonable levels of agreement in their rankings. By contrast, their ratings were not well correlated with the UK classification, but the rank ordering was much the same as earlier rankings of drugs that took harms into account. The UK classification has been developed over nearly a century by small changing groups of experts. The information available to them on the harms that newer drugs cause has varied in quantity and quality, and, in the face of uncertainty, prudence has often led to drugs receiving the most risky classification, with limited opportunity to later revise these rankings. By contrast, Nutt and colleagues asked experts to compare the risks of various drugs (including alcohol and tobacco) on many dimensions of harm, gave the opportunity to revise ratings in the light of those of the group, and used statistics to derive overall rankings. Nonetheless, there remain major impediments to the adoption of policies that are better aligned with drug-related harms. Those who believe, for example, that legal penalties should be proportionate to the harm that drug use causes would argue that we should reduce penalties for use of the least harmful of the currently illicit drugs, among which cannabis would be the leading contender. The rankings also suggest the need for better regulation of the more harmful drugs that are currently legal (ie, tobacco and alcohol). The wealthy, well organised, powerful, and politically connected alcohol and tobacco industries will be able to resist policies that would more effectively reduce the harms that their products cause. Several millennia of human experience with alcohol, its pervasiveness in industrialised cultures, and the US experience with alcohol prohibition (1920–32) make it unlikely that any industrialised society will criminalise alcohol use. But that still leaves plenty of room for more effective use of taxation and regulatory controls to reduce alcohol-related harm. Populism favours tough policies towards illicit drugs such as cannabis. Psychoactive drugs (other than alcohol and tobacco) remain the last holdout of the most restrictive form of regulation—criminal prohibition—despite the enthusiastic embrace of market deregulation almost everywhere else. This situation could change if the USA embraced a free market regime for all psychoactive drugs. But as attractive as this approach may be to libertarians, it would not be good public-health policy. Allowing a free market for all currently illicit drugs would add substantially to the harms now caused by alcohol and tobacco. The work of Nutt and colleagues is a useful step towards a better evidence base for the formulation of drug policy. They challenge us to find ways to reduce the indefensible disparity between the regulatory treatment of alcohol and tobacco and the most widely used illicit drug, cannabis. The solution could involve a combination of increasing restrictions on the promotion and availability of alcohol and tobacco, while reducing the severity of the statutory penalties for cannabis users. More rational policies would also avoid thought-avoiding rhetoric such as the so-called war on drugs. Instead, we need to find better ways to reduce the demand for all psychoactive drugs by the youth of developed countries. And we need more humane and effective responses to people who become dependent on psychoactive drugs, despite our best efforts to discourage their use.