National drug control initiatives often lack an evidence base, while existing international treaties have done little to prevent drug misuse, say experts in a series of studies published in the Lancet.

Every year some 200 million people worldwide use illicit drugs, and the burden of drug use in developed countries is similar to that caused by alcohol, shows one of the studies (Lancet 2012;379:55-70, doi:10.1016/S0140-6736(11)61138-0).

Speaking at a press briefing to launch the series, John Strang, head of the National Addiction Centre at King’s College London and author of a study on the success of drug policies in different countries, said that “policy makers have pursued many drug control initiatives that lack scientific evidence for their effectiveness and that can cause harm through unintended consequences.”

He added, “Much public debate in drug policy is only minimally informed by scientific evidence. Values and political processes are important drivers of drug policy, but evidence of effectiveness and cost effectiveness can help the public and policy makers to select policies that best achieve agreed goals.”